diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_tx.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_tx.0.png
index bd5fba698d..8d8144167b 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_tx.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_tx.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_ty.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_ty.0.png
index 6e8ee48464..917c5807c8 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_ty.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_ty.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_tz.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_tz.0.png
index d5cb8f5bc8..b03b26f126 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_tz.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_tz.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_yx.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_yx.0.png
index 55c83922bd..fe8bef6d9d 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_yx.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_yx.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_zx.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_zx.0.png
index e924aaed82..0fd6f3120c 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_zx.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_zx.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_zy.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_zy.0.png
index 03167fc589..b8a9611d34 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_zy.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestContour.test_zy.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_tx.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_tx.0.png
index ea362eed91..504f1bcdc5 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_tx.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_tx.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_ty.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_ty.0.png
index 75aadb5f91..19c2133b73 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_ty.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_ty.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_tz.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_tz.0.png
index a7dd4db7a7..30bcf9e0a6 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_tz.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_tz.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_yx.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_yx.0.png
index f88dc3cb51..2c8370f0b2 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_yx.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_yx.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_zx.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_zx.0.png
index 31f4f3b3f4..a0a1707078 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_zx.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_zx.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_zy.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_zy.0.png
index d86f6e7d8e..626dbfd23a 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_zy.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestContourf.test_zy.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestFillContinents.test_fillcontinents_ontop.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestFillContinents.test_fillcontinents_ontop.0.png
index 314d524961..80b3823603 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestFillContinents.test_fillcontinents_ontop.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestFillContinents.test_fillcontinents_ontop.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestFillContinents.test_fillcontinents_underneath.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestFillContinents.test_fillcontinents_underneath.0.png
index 46fa8f3dea..c20e3afa64 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestFillContinents.test_fillcontinents_underneath.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestFillContinents.test_fillcontinents_underneath.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestHybridHeight.test_bounds.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestHybridHeight.test_bounds.0.png
index 45652b88e8..0b40452576 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestHybridHeight.test_bounds.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestHybridHeight.test_bounds.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestHybridHeight.test_orography.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestHybridHeight.test_orography.0.png
index ab59067672..3a210f660a 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestHybridHeight.test_orography.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestHybridHeight.test_orography.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestHybridHeight.test_points.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestHybridHeight.test_points.0.png
index af43ddd459..59043d07cd 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestHybridHeight.test_points.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestHybridHeight.test_points.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestMissingCoord.test_no_u.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestMissingCoord.test_no_u.0.png
index de0e7d9954..406c95bbe8 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestMissingCoord.test_no_u.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestMissingCoord.test_no_u.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestMissingCoord.test_no_v.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestMissingCoord.test_no_v.0.png
index 88aa300e27..a78e30f874 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestMissingCoord.test_no_v.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestMissingCoord.test_no_v.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestMissingCoord.test_none.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestMissingCoord.test_none.0.png
index d1c5d2d8cc..706851aae7 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestMissingCoord.test_none.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestMissingCoord.test_none.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_tx.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_tx.0.png
index 7e15fb3d3a..29f6dbaa7e 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_tx.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_tx.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_ty.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_ty.0.png
index 956a017bb8..8622ee4088 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_ty.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_ty.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_tz.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_tz.0.png
index 12b8f97b42..8446f1cc02 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_tz.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_tz.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_yx.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_yx.0.png
index f24a6c653b..6455fa6124 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_yx.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_yx.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_zx.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_zx.0.png
index f125b18a32..bce14142a1 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_zx.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_zx.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_zy.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_zy.0.png
index 859be893dc..74ef63c138 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_zy.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPcolor.test_zy.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_tx.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_tx.0.png
index 0b54f1d786..12dc6ec423 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_tx.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_tx.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_ty.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_ty.0.png
index 27ade70012..df72586c71 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_ty.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_ty.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_tz.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_tz.0.png
index 77748085ad..3407df85d4 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_tz.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_tz.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_yx.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_yx.0.png
index 7070d9e455..ffeaca6304 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_yx.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_yx.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_zx.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_zx.0.png
index 2d87c3f432..5bd609b39d 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_zx.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_zx.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_zy.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_zy.0.png
index 6df3881c08..7263803ce3 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_zy.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPcolormesh.test_zy.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPlot.test_t_dates.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPlot.test_t_dates.0.png
index 0e092a01ee..26db294ec5 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPlot.test_t_dates.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPlot.test_t_dates.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPlot.test_y.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPlot.test_y.0.png
index 579b167fb2..fb8f51b7d9 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPlot.test_y.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPlot.test_y.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPlot.test_z.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPlot.test_z.0.png
index 66460d2100..ef5a3f5c4e 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPlot.test_z.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPlot.test_z.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPlotCoordinatesGiven.test_non_cube_coordinate.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPlotCoordinatesGiven.test_non_cube_coordinate.0.png
index 96533cf5b3..61783cb58e 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPlotCoordinatesGiven.test_non_cube_coordinate.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPlotCoordinatesGiven.test_non_cube_coordinate.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPlotCoordinatesGiven.test_tx.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPlotCoordinatesGiven.test_tx.0.png
index 548c82498b..f9fa5fec80 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPlotCoordinatesGiven.test_tx.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPlotCoordinatesGiven.test_tx.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPlotCoordinatesGiven.test_yx.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPlotCoordinatesGiven.test_yx.0.png
index d818c23ca6..1b6fcc6e20 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPlotCoordinatesGiven.test_yx.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPlotCoordinatesGiven.test_yx.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestPlotCoordinatesGiven.test_zx.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestPlotCoordinatesGiven.test_zx.0.png
index f19da1dc93..63cd34b2ce 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestPlotCoordinatesGiven.test_zx.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestPlotCoordinatesGiven.test_zx.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestQuickplotPlot.test_t_dates.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestQuickplotPlot.test_t_dates.0.png
index 9cea0fc2e5..48392d94e2 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestQuickplotPlot.test_t_dates.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestQuickplotPlot.test_t_dates.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestQuickplotPlot.test_y.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestQuickplotPlot.test_y.0.png
index 952c8f3ee1..9e041e5659 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestQuickplotPlot.test_y.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestQuickplotPlot.test_y.0.png differ
diff --git a/lib/iris/tests/results/visual_tests/test_plot.TestQuickplotPlot.test_z.0.png b/lib/iris/tests/results/visual_tests/test_plot.TestQuickplotPlot.test_z.0.png
index 422ec85e5d..3698a2c599 100644
Binary files a/lib/iris/tests/results/visual_tests/test_plot.TestQuickplotPlot.test_z.0.png and b/lib/iris/tests/results/visual_tests/test_plot.TestQuickplotPlot.test_z.0.png differ