Text in Widget Multiline Editable Text doesn't change its color after compilation?

I am trying to make a black button with a white text. I’ve changed the ‘Color’ property in text style properties group, it showed me the text recolored in the viewport window. It remained the same after compilation.
However, when I start this widget, the text remains black as it was in defaults.

This is the viewport:

and this is what i see when i play:

Note: i have put the black background here. At first i thought the button was just behind it, bu I’ve tried to remove it, and the button didn’t appear.

Do anyone know if it is a bug or I’m doing something wrong?
Thanks in advance