Joining a new color

Hello, I’m a first timer, I am knitting a christimas stocking with stripes of three different colors, the first color change went fine, then when I went to add the next color it is showing through on the right side. I have watched all the video’s I can find but I’m not sure where I went wrong. Any help would be appreciated.
thank you

Is just the tail stitcking through? Make sure when you knit the first stitch of the new color that you don’t wrap the yarn around the old yarn. Maybe a picture would help us figure out the problem?

If you stocking is in garter stitch, you may have changed the colors on the ws row rather than a rs row. Then you’d have the purl bump showing two colors on the front.