Harry Potter Scarf

I want to knit a harry potter scarf but I am concerned about switching from one color to the next (as I typed this I just got an idea could I cast on to the right needle when I’m ready to switch and then knit it on from there?) anyways can anyone help me your help will be greatly appreciated

This is how to do it:

go to this page - http://www.knittinghelp.com/knitting/basic_techniques/misc.php

and look at the video for duplicate stitch join.

I am doing a Harry Potter in Ravenclaw colors. Welcome to the forum!