Undo old side discolor fix

Undoing the one-line colormap bleeding fix in !427 (merged) so we can be careful right before release.

I'm 90% sure the code is okay without negative side effects, but it would be a nice change of pace for me not to approve a merge so hastily.

For Jimita's branch, this would mean merging the latest master into his branch, and making sure nothing is changed in conflict resolution.

Updated code in !429 (closed).