This looks great. Two things that got me though...
The "picker" tool does not do what I thought it would. And for the modifier classes I'd rather see the word than the color if I had to choose one of the other. I.e. "danger" instead of a red square.
One of my favorite things about bootstrap is the way class naming is semantic -- it denotes purpose not color. So using a color picker looking square to change the modifier seems non-intuitive to me.
The "picker" tool does not do what I thought it would. And for the modifier classes I'd rather see the word than the color if I had to choose one of the other. I.e. "danger" instead of a red square.
One of my favorite things about bootstrap is the way class naming is semantic -- it denotes purpose not color. So using a color picker looking square to change the modifier seems non-intuitive to me.