Welcome. This must be intarsia day as someone else just asked this question. It's a common one, too.
Some say that it's ok to just tie the new color on. There is a site dedicated to intarsia that says that, and Kaffe Fassett, who has books on the subject just ties. I've done it, and it works ok.
You can also catch the end of the new color a few stitches before the color change so the first color stitch looks more like a regular stitch. Just kind of twist the new color in with the back of the old color.
"Trust the pattern!"
Time flies like an arrow, but fruit flies like a banana.
Hop aboard while we follow the cloud-covered van of knitting harmony, man!! Woooo!! --Hedgehog
IngridKH on Ravelry