It's interesting how my perspective has changed after the 3rd child.  I tend to let a lot of things slide with Clay.  He doesn't have a crib sheet, a changing table cover, doesn't get hair cuts :) and he's way behind the other boys on his 'knowledge' of colors, counting, shapes, etc.  He has 'baby of the family' written all over him.  Rod and i joke that he obviously must be color blind since he doesn't know colors yet.  ha ha.  more like he couldn't care less what color is what. 
Here is Ben leading a color lesson, asking what color is the grass.  (We would have excepted green or brown:)  I think we will wait to revisit colors until he's 3!  i know these things will come when he's ready.