How do you cast on with two colors?

Hi everyone! I have a question for you…I was watching the video for fair isle knitting with two colors, but I don’t know how to cast on with both colors. Do you hold them together as if you were tweeding, or do you alternate colors? I’m trying to follow a chart but I’m having trouble getting started. Thanks!


Usually you cast on with the background color only and then introduce the second color when it’s called for.

Wouldn’t it also make the cast on too bulky?