The combination looks really nice and is an interesting concept. When putting 3 different colors together, will they remain true?

The reason that I said this is because few years ago, I planted different colors hibiscus in one of my past gardens, some of them died and I ended with mostly red and pinks, After a while, they all got a shade of red...and I don't know why.:)

Silvia

I've done this before. Yes, Silvia, they will remain true. Tropical hibiscus aren't that easy to cross-pollinate. If the ones you planted were the fancy hybrids, they are grafted onto red and pink rootstocks, the two hardiest ones there are. When they die back, the bush comes back from the roots. If they didn't die back, probably the top died out (those fancy hybrids are very weak plants) without you noticing it, and the rootstock took over, or the rootstock just sprouted out at the bottom and took over the bed.