Change CoregistrationUI status bar text color to black

[hoechenberger]

Somehow Qt applies a weird color scheme to the status bar on macOS and the text color is white by default, which makes it barely readable. This PR changes the text color to black.

main	PR

cc @GuillaumeFavelier @agramfort

[GuillaumeFavelier]

I tested those changes locally and it actually affects qdarkstyle's dark theme, I think it decreases the contrast for me (look at the color of Press ? for help in the status bar):

main	PR

import os
import mne
from mne.datasets import sample


data_path = sample.data_path()
sample_dir = os.path.join(data_path, 'MEG', 'sample')
subjects_dir = os.path.join(data_path, 'subjects')
fname_stc = os.path.join(sample_dir, 'sample_audvis-meg')
stc = mne.read_source_estimate(fname_stc, subject='sample')
initial_time = 0.096
mne.viz.set_3d_backend('pyvista')

brain = stc.plot(subjects_dir=subjects_dir, initial_time=initial_time,
                 clim=dict(kind='value', lims=[3, 6, 9]),
                 size=600,
                 hemi='rh',
                 views=['lat', 'med'],
                 brain_kwargs=dict(block=True, theme='dark'),
                 )

Let's work on it together to find a solution that can work for everyone @hoechenberger

[hoechenberger]

Yes let's try to find a solution that doesn't override the qdarkstyle stylesheets

[GuillaumeFavelier]

This issue might be fixed by #10456?