Add setter for colors property

[chrisjonesBSU]

This PR adds a way to manually set colors besides using a dictionary with particle_type:color pairings. For example, to set different colors for the first half and second half of particles by count:

Here is a quick example. It's from the welding tutorial in hoomd_organics:

sim_viewer = FresnelGSD(gsd_file="tensile.gsd", view_axis=(0, 1, 0), frame=-1, height=16)
weld_colors = np.zeros_like(sim_viewer.positions)
weld_colors[:weld_colors.shape[0]//2 + 1] = np.array([0.5, 0.25, 0.5])
weld_colors[weld_colors.shape[0]//2 + 1:] = np.array([0.5, 0.1, 0.1])
sim_viewer.colors = weld_colors

[codecov]

Codecov Report

Merging #58 (27c6fb3) into master (d13ab94) will decrease coverage by 0.14%.
The diff coverage is 80.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #58      +/-   ##
==========================================
- Coverage   96.08%   95.95%   -0.14%     
==========================================
  Files           8        8              
  Lines         638      642       +4     
==========================================
+ Hits          613      616       +3     
- Misses         25       26       +1     

Files Changed	Coverage Δ
cmeutils/visualize.py	96.89% <80.00%> (-0.47%)	⬇️