Use new skipPECheckOnAddAtom to allow user to drag atoms close

[#74687984]
Use black background, slightly denser clouds

[#74687984]
Make interaction text a small "attractive" when far

[#74687984]
Set proton to blue in first interactive

This is done via script rather than edit to model, as the second
bond interactive uses the "real" colors.

[#74687984]