How do I check if the car seat is at the correct recline angle?

When using the carrier with the base, check the recline indicator on the base to ensure it shows only green (for 20-35 lbs/9.1-15.9 kg) or only blue (for 4-20 lbs/1.8-9.1 kg), but never both colors showing at the same time. If the foot is in the lowest position and the indicator still shows mixed colors, place a tightly rolled towel under the foot end of the base to adjust the recline. Never place a towel under the child's head end. (Pages 70-71)