Color tweaks.

[Eric-Vin]

Description

Updated color specification process to ensure we have a unified internal representation and ensure we pass colors to Trimesh in the correct form. Tested on test suite and examples.

Issue Link

N/A

Checklist

• [x] I have tested the changes locally via pytest and/or other means
• [x] I have added or updated relevant documentation
• [x] I have autoformatted the code with black and isort
• [ ] I have added test cases (if applicable)

Additional Notes

N/A

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 90.00000% with 2 lines in your changes are missing coverage. Please review.

Project coverage is 86.13%. Comparing base (7f018e0) to head (5f333fe).

Files	Patch %	Lines
src/scenic/core/object_types.py	66.66%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #240 +/- ## ======================================= Coverage 86.13% 86.13% ======================================= Files 144 144 Lines 24938 24956 +18 ======================================= + Hits 21480 21497 +17 - Misses 3458 3459 +1 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[Eric-Vin]

Unfortunately I haven't found a way to open the Trimesh viewer when running pytest, at least on my machine. I can definitely add the length test though.