Numbers and colors

It has been quite a while that Sophia stopped at three, number three. She only counts 1, 2, 3. It looks very hard for her to get over 3. I gave up and started to teach her colors.
I used the book "Brown brown bear what do you see?". She loves the book and repeats almost everything I read in the book. She is able to repeat all the colors I read to her but not able to recognize any of them except green. Whenever I ask her what color, she will say "Green!". Maybe everything is green in her eyes, who knows.
Today, when we were shopping in the store she played with my happy weekly planner. She showed off to everyone that passed by. Suddenly she said "yellow" and showed the yellow happy face sticker. Wow, she knows color now!