How many colors should a 4 year old know?

Your 4 year old may be able to recognize several colors! Many children are ready to begin learning about colors as early as 18 months.  Colors appear everywhere in the world, have fun naming the colors your child sees every day. Start slowly and introduce one color at a time. As your child learns to identify different colors, have them sort objects by color to help reinforce what they are learning.  Practice often with short flash card sessions and give your child lots of positive encouragement as they work on color recognition.