Joining new color yarn

I have found posts on how to join a new color & they are helpful. I’m knitting scarves for charity - simple pattern but each stripe is k2, p2 ribbing. When I join the new color in the ribbing it just looks like a hot mess! Please help

What looks messy? Is it the loose stitches at the ends where the new yarn was joined? You can snug those sts up later by a slight pull on the yarn ends. If you’re carrying the unused yarn up the sides of short stripes, you can make sure that there’s a slight bit of tension on the carried strand when you start to use it again.

Is it the way the knit purl rib looks with the old color showing through (Techknitter calls this “icky dots”)?

thank you salmonmac! I learned lots from your post. My problem was icky dots! I never would have knitted across a ribbed row to solve the problem. Came out really well. Thanks:woot: