Value organization in a Granny Square

Ahhh... The Granny Square.
There's more to it than meets the eye!

I thought that if I just picked out random colors to crochet together, I would magically turn out a afghan that would be the cat's ass... boy was I wrong. It takes planning to make the colors work. For the longest time I couldn't figure out why I like some blocks and others I just didn't??

Then I realized...

Following a pattern of value makes a BIG difference. Instead of throwing together color combinations, I started with a plan: the lightest value in the center, then introduce a medium value for the middle color, and finish with a dark value on the outer edges, like this...
And for some reason, after I made this square it clicked.

Here's another square that works.
Notice the light blue, then medium purple, then a darker purple.Below is one that is not so good...
Even thought I like all the colors in the square below, I felt that it just didn't work.There wasn't enough differentiation between the values of the colors.

Yeah for me that I figured out the importance of value, but boo that I have to start my Granny all over :(