I was reading about natural coloring with herbs & infusions. Most of what I've read talks about infusing the oils used. Recently though, I came across a post where the soaper infused the GM they had used and got a brighter color. I can't remember where I read it, I think it was either on here or on one of the linked-to blogs from here. (I've read so much that it's all starting to blur together. )
I
think the herb used was annato seed and I
think the end color was a brighter yellow. (again, a blur

)
In any case, I was wondering, how would I go about the GM infusion? Do you heat the GM with the herb like a tea? Or do you put it in the cold GM and let it sit in the fridge for a few days? Do you then freeze your GM for the slushie? Or do you use your GM as liquid?
TIA!