Is there a problem putting paprika on top of egg salad for looks. Would it be tzoyveya?
This is permitted.
Something commonly done for spicing and for the taste of the food, is permissible even when done for the looks. Something which is used specifically for coloring purposes [such as food coloring] is a dispute whether the melacha of tzovea appies, and this should be avoided.
In any event, sprinkling paprika would be permitted as it does not color the food, but rather sirs on top in a decorative way.
Shulchan Aruch O:C 320:19, Chacham Tzvi 92, Chaye Adam 22:5, Mishna Brura 340:26, Pri Megadim 320:22