Need help--how do I switch colors/stitches within a row?

[Beauty4Ashes]

http://www.lionbrand.com/patterns/cbs-babyHeirloomSet.html?noImages=

AFGHAN

SQUARE – Make 20

With C, ch 10 and join in a ring with a slip st n first ch.

Rnd 1 Work beg popcorn in ring, ch 3, (popcorn in ring, ch 3) 7 times, join with a slip st to top of beg popcorn. Fasten off.

Rnd 2 With RS facing, join B with a slip st in any ch-3 space, work (popcorn, ch 3, popcorn) in same space, *changing to A in last popcorn, ch 1, 3 dc in ch space, ch 1, change to B, (popcorn, ch 3, popcorn) in next space*, repeat from * to * 2 times more, end with A, ch 1, 3 dc in last space, ch 1, slip st to first popcorn (3 dc between popcorns). Fasten off.

I understand that I'm supposed to switch from the popcorn stitch in pink to double crochet in white without fastening off between stitches, but how? I can visualize how it will end up looking, the popcorn stitches will form the corners and the dc, the sides of the square.

[TestifyToLove]

In the last step of the stitch before the color change, you loop the new color in. You will then carry the color not in use inside the stitches until you need to change them again. Just keep the non-used color strand next to the already formed row and construct your stitch around it.

[Beauty4Ashes]

If I understood you correctly, once I weave in the second color, I'll be working the two colors throughout the round. There seems to be something wrong with my gauge. I did 2 rows and it looks like a hat, it doesn't lay flat.

[TestifyToLove]

I'd do a guage swatch but also be careful to not change tension when changing colors. And, yes, you would be working with 2 colors throughout but only one will be seen.