If you tap the (i) icon it tells you what colour you will get from it. Mine works exactly as specified.
the small one gives you 75 common color every 12 hours (which is given free during easter quest) the big one costs donuts gives you 300 uncommon color every 24 hours.
You probably have your term "common" mixed with "preferred". Whatever color the zapped bunnies give you more often is "common" same with when tapping neighbors the "common" you get multiple of at once but lowers after X amount of taps and 1 "uncommon" in same tap
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