How to turn 'beginning of baby beanie' into 'oh I was just swatching for fun' - forget the really simple, basic guidelines for crocheting a flat circle, and start with 8 sts when working in single crochet, and wind up with a circle that begins to ruffle. I think single crochet at this particular gauge was going to wind up too firm anyway, so score 1 for color study.
This will vary based on gauge, yarn, desired results, etc., but for a basic flat circle I use the following guidelines:
single crochet: begin with 6 stitches, increase 6 stitches each round.
half-double crochet: begin with 8 stitches, increase 8 stitches each round.
double crochet: begin with 10 - 12 stitches, increase 10 - 12 stitches each round.
triple crochet: begin with 12 - 14 stitches, increase 12 - 14 stitches each round.
For those using UK terminology:
US single crochet = UK double crochet
US half-double crochet = UK half-treble crochet
US double crochet = UK treble crochet
US triple crochet = UK double-treble crochet