It's true, toddlers love to sort! I'm not sure Baby Bear even realizes he's doing it, but whenever he is presented with objects of various colors in which there is repetition of colors, he starts sorting. For example, the blue letter blocks that came with his Vtech Sit to Stand Alphabet Train often end up in a pile together on the floor (no, that's not a plug, just information in case someone likes the toy in the picture :) ). Sometimes he does this with the red or orange blocks, but for now it's almost always the blue.
Other items Baby Bear likes to sort by color:
The food on his plate
Basically, any small and easy to manipulate colorful objects get sorted. He has fun, and it's a great skill for toddlers to practice and learn!