How to add "Size" option in my Commerce Product without adding lot of SKU that differs by size? The same question was "Module Commerce Product Option. Sizes are not active for selection"

I read here Drupal Commerce Custom Sizes that "it requires you to define a SKU for every possible combination - depending on how many measurements options you have"
But I do not want to add many products. I need to add One product display Woman's T-Shirt with 5 SKU with photos:
Blue, White, Yellow, Green, Orange.
In every SKU I want to check the option sizes like:


Blue with option sizes: S, L 
White S, M, L, XL,
Yellow XL, XXL, XXXL
Green L, XL, XXXL
Orange S, L


Without adding lot of SKU like: T-Shirt White S, T-Shirt White M, T-Shirt White L.....

The option Sizes should become dropdown or checkboxes when customer is viewing product Womans T-Shirt. How to do this?

Here it is correct: http://demo.commerceguys.com/ck/tops/drupal-commerce-hoodie
The user can choose color and size. Is this really neccessary to add all variations with color and sizes?

How to solve my optimization problem?
You're going to create 5 option set.


White with sizes
Blue with sizes
Green with sizes
Orange with sizes
Yellow with sizes


Each Option set create you created insert your size field (list type)

On your Shirt product type or whatever your product type is, create your sizes option set reference field

So when you create your 5 SKU you're going to choose which option set the user is going to use.

For Example:


Woman's T-Shirt WHITE (PRODUCT) 
Option set reference:"White with    sizes"