Basically we're going for blue and yellow here. Any shade of blue, any shade of yellow.
For the block itself we are going to be using our improvisational piecing skills. I know you've got 'em!
I made this block up so I'll give you a little tutorial.
The idea I'm going for are blue "raindrops" on a sunny background.
Start with some blue and yellow scraps or strips.
Piece them together until they are about 11-12" in length. Trim the edges up, making the width of the strips whatever you like. I varied mine and made sure they weren't smaller than 1.5" wide. You could also piece together a couple different strip sets and then chop them up at different widths for these pieces.
Now cut some strips of yellow that are about 11-12" long and sew them to the long edges of your pieced strips. These can be whatever width you like, also.
Trim and square up your block to be 10.5" and you are all set!
Have fun!