Consider uninstrumenting colors in next release

[arouinfar]

In phetsims/scenery#1607 we discovered that colors customized in Studio are overwritten when switching between color profiles. This issue will be addressed by an MR, but while investigating we saw that GAO has these instrumented colors:

I don't think the design team made an explicit decision to expose these colors to clients, and it probably snuck in during the early days of instrumenting colors. We wouldn't typically instrument these colors, so let's consider uninstrumenting them in the next release.