Updates atom alpha when atom color is set

[Ruzihm]

When setting atom color (but not with matrix), update alpha variable with alpha channel of color

#1738

[wixoaGit]

Do you have an example of what this is fixing?
Nevermind, didn't see the linked issue

[Ruzihm]

From the discord:

amylizzle: oh I guess atom.alpha is just an alias for atom.color.A

So this isn't appropriate. Going to mark as draft and revisit.