How to use the new Variables with existing variables?

Hey guys. I’ve looked at some videos on how to use the new Variables function in Figma and I’ve tested it a bit. What I find backwards is that I’ve already defined all my base color variables. So why can’t I import existing variables into the new Variables feature?

Also, if I have an exiting design, does it mean I have to go to each component and select the new color variable?

Isn’t there an easier way to start using Variables on an existing project?