LIFX Z - blackout LEDs not using?

Considering running Z strips for bookcase shelving… lot of 14" wide shelves… in total one starter kit and two extensions will do it including vertical links up to next shelf. Jump strips seem poor solution due to wrong length sections and inability to cut any but last strip. Starter kit for each shelf way too expensive and want all shelves to be on/off and colored identically.

Has anyone blacked out or somehow covered LEDs not wanted (the vertical rises between shelves in my case) so they become hidden? Know they get hot. Paint with black stove/engine block (high heat) paint? Suggestions?