Add color parameter to mne.viz.plot_sensors function

[timonmerk]

Describe the new feature or enhancement

A color parameter being of shape (n_sensors, color) would be a great addition for visualization in the mne.viz.plot_sensors function.

E.g. currently in the ECoG Plotting Tutorial https://mne.tools/stable/auto_tutorials/clinical/30_ecog.html#sphx-glr-auto-tutorials-clinical-30-ecog-py only one color for all sensor locations are used by default. I looked up in the used function _plot_sensors() in mne.viz._3d.py that the function _plot_glyphs() is called which uses a a single tuple color (1.0,1.0,1.0) for all sensor locations.

I am not sure how easy that would be to adapt, but certainly a great addition!

Describe your proposed implementation

Additional function parameter in the function mne.viz.plot_sensors

Describe possible alternatives

Otherwise the renderer in mne.viz._3d.py would need to be called for every individual sensor with a single color:

renderer.sphere(center=loc[loc_idx, :], color=color, scale=scale,
                               opacity=opacity,
                               backface_culling=backface_culling)

Additional context

No response

[agramfort]

sounds good to me

[drammock]

All in attendance at today's dev meeting said this seems useful. @timonmerk are you up for doing the PR?

[timonmerk]

@drammock Sounds great! I'll give it a try and reference this issue with the PR