Remove outdated warning for colors and update some colors

[Jay-o-Way]

Description

• Removed the warning about the availability for some color brushes.
• Updated ColorTile to accommodate acrylic/mica background.

Motivation and Context

Outdated.
Fixes #2153

How Has This Been Tested?

Screenshots (if appropriate):

Gallery.Background.mp4

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

To-do

• check spelling and interpunction: "color" versus" colors"; do descriptions explanations end with a period or not?
• find out why the Smoke preview is...weird (it doesn't change color)

[niels9001]

@Jay-o-Way

I just checked, some of the brushes are actually shipping in WinUI but then some of them are not:

ControlFillColorQuarternaryBrush
SolidBackgroundFillColorSenaryBrush
SolidBackgroundFillColorQuinaryBrush

Not:
MicaBackgroundFillColorBaseBrush
MicaBackgroundFillColorBaseAltBrush
CardBackgroundTertiaryBrush

EDIT: turns out we do have a brush in WinUI for CardBackgroundTertiaryBrush -> it should be CardBackgroundFillColorTertiaryBrush

[niels9001]

Addressing comments in this PR: Jay-o-Way#1

[Jay-o-Way]

Thanks Niels! Got some advice for the two extra points?

[niels9001]

• Yeah, let's keep the period for the category description and not have it for the brush description (as those are pretty short for most of them). That's inline with what the Figma toolkit has. So:

• This is expected. The Smoke color values are the same for both Dark and Light theme: https://github.com/microsoft/microsoft-ui-xaml/blob/abb359150eaa4c8ba1c8dd89d81552cbf4e2d557/src/controls/dev/CommonStyles/Common_themeresources_any.xaml#L149 (search for SmokeFillColorDefault)