I know I'm the only one who thinks this, but...
It's surely purple. Why? Because their relationship was a real fairytale. They were so cute and lovely but we all know they weren't endgame since the beginnig. So at the beginnig it was pink , the colour of their love.
But this pink has turned into purple.
With all the secrets, drama and lies,it's all turned darker.
They will always love each other, but they won't be a couple:
they have other lovers <3 (Nate/Vanessa oR Blair)

Sometimes cute, but boring!!!!!

^agree

Happy

It represents bittersweetness which is what Derena are; a sweet but distant memory that's had it's time.

Black :/