As per the Clash Royale Reddit Community, Super Cell will be removing the font colour feature in the next update and your name will be staying with the color codes. For example, if you have color on your name then after the removing of the color your name will appear as <c2>Your Name</c>
This will look terrible? Don't worry, Super Cell has got you. They will provide you a free name change to correct your mistake.
Now the question comes, why Super Cell is doing this? This isn't affecting anything! On this Question, Super Cell gave a reasonable answer.
The next update will be hitting the store probably on the middle of the April with some cool new features too.
Enjoy your colorful names till the next update!