Here are some pictures of my collection:
My bowls: 3 404's, 3 403's, 3 402's, and 4 404's
My primary bowl set: Green 404, yellow 403, red 402, & blue 401
Greens: These are my spring & summer pyrex pieces.
The lid on this one was found by itself at a thrift store, but when I brought it home I found the perfect lidless partner for it. They were made for each other.
These are my fall/winter pieces.
My yellow 403 primary on top, and the yellow 404 primary on bottom. See the difference between the 2?