I wonder why people like owls so much. I think it's because owls have faces; they look like little persons to us. This owl is definitely a person! Not only it wears a hat and a coat, it also knows how to use an umbrella. Oops, it's not using it on the mittens, but it's because the rain has just started ).
The colors on the charts are just one example - use any colors you like. I do recommend to use dark for CC and light for MC, the reverse may look blurred.
For the ribbing, I would do no more than 4-5 cm of 2x2 rib on 64 stitches, and than added 6 st evenly in the first chart row.
The pattern is in pictorial form; everything is clearly charted in full color, but there's no written instructions.
30 X 30 = 10 cm