idk which one ur talking abt cuz i dont see anything rgb (or the way how i would describe it) since it's just color flicker and text glitch effect (via text shadow)

color flicker on name:
https://www.w3schools.com/code/tryit.asp?filename=GUJ0433SBCDW

text glitch code:
text-shadow: -1.5px 0px 0px #fc0d0d, 1.5px 0px 0px #0db8fc;