Painting Rubber ???

Trying to do my own version of
D I Y cup holders
Wanted to match the green-ring theme started by the vent rings


So I bought the “fernco “ 3x3 pluming fittings suggested by another member and proceeded to spray paint them
First with white then followed by GREEN - was doing this in a hurry while doing other things- so might not have waited till “dry” between coats

PROBLEM is it’s been over 48 hrs and green is still TACKY - I want to spray a clear finish coat but don’t know if I should since green has not dried

This is my first attempt at painting rubber -
Is the rubber the problem or rushing the other coats the issue ???
Or it’s just going to take longer then I assumed ???