Making other elements follow the color choice of another element

Making other elements follow the color choice of another element.

 I'm creating a Sign Shoppe website for a customer. the customer has a section that you pick the sign and you add the text that you want to have in your sign. The issue is that the sign are only one color.

1- sign #1

color back ground they can change the color of the background they only have 4 different color to choose from, but the text is going to be only in white. the customer can add they own text it always come first as white, but when they click on the text to change the size or to edit the text the color shows white box and a black box for the color and they can change the color to black, how can I take out the black color from there, also I want if they add another text line to be the same color that they chose before.

2- sign#2

The back ground will be white always, but the text they can choose from 4 different color, but is going to be a 1 color sign so they can only choose the text in only one color. How can do it that when they choose the first line color, all the other line will be the same color. i don't want hem to choose the first line in red and the 2nd line blue, only one color