Colored Nail Tips: Removal or Overlay?

Question
I currently have Pink & White acrylics. I want to get those Sparkly colored tips. So do i have to get my acrylics taken off and have completely new ones applied, or do they put the colored acrylic over the white or what? thanks.

Answer
It depend on you nail's tech way of working but i wouldn't remove them, it isn't necessary, i woulod only thin the out then apply the new coloured acrylic.
Hope i could help.
Sorry for taking longer than usual to reply but i've been having some problems conecting to the internet.