Change color on text

Its in a separate BP, but i have already enabled the input on Player 0.
But it works once, the color gets changed, so it kind of works. its when i press a second time nothing happens. And i can see that RandomStream seeds a new value, cos I print it to screen. But the color on the text component is not changing. Of course i can change to use materials, but I want to understand what is happening here.