In general (on Asus ROG boards) the colors have a significance regarding safety: white - safe; yellow - your responsibility (usually means that left the safety zones, like for the VRAM by default is 1.2V, but the XMP is usually raising it to 1.35V); purple - unsafe (without proper cooling); red - dangerous (this usually is for liquid nitrogen)
It is all depending on your cooling solution - i.e. check your temps!
On older boards I have run voltages in the purple zone (Vcore, VRAM, VCCIO, VCCSA), but then I was in the OC game... nowadays, I am going for safety - meaning good temps with quiet cooling*