Or, couldn't you just make the PL1 and the score, two separate text objects? Then its easy to set each color. Just a thought, I'm a newb so maybe I'm missing something.
I use to do that also, but in this case, I have the score in the center, so it always will be in the center when I add score, then the score will overlap the name I use before the score "PL1 000, 000, 000" and "PL2 000, 000, 000". But I got it to work with Textmesh Pro. If I want the name PL1 to be white and the score in red, then it will be something like this:
<color="white"> PL1 <color="red"> 000, 000, 000
Or if you want to use hex colors:
<color=#FFFFFFFF> to get white.