I heard that switching colours in crochet work in order to make a picture is called "tapestry crochet". I've only ever tried this with knitting (where it's known as "intarsia"). I thought it would be fun to make a Christmas Bauble with tapestry crochet.
Because it's in-the-round, the stitches are offset from the ones below and I had to make up some special crochet graph paper to draw the design. I've gone for reindeer, and I'm telling you that because I'm less-than-pleased with the result and I think you'll need telling what I was aiming for (whoops).
Firstly, I tried to align my increases and decreases to give me more space for the design. While this works with knitting (because knitting is stretchy), it doesn't work for crochet (because it's firmer) and the result is a slightly wonky and lumpy ball.
Secondly, my choice of pale blue and white was poor because there is not enough contrast to see single stitches in the design, which is why the reindeer looks like it has only three legs.
Gah. It's now too close to Christmas to fix this pattern ready for release, so I've got another 340 days to perfect this one...