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One day I thought it would be different to send our 7 yr. old daughter to
school with a rainbow colored gf sandwich bread, and what a hit it was.  Now
all her gluten friends think she's got the coolest bread in town. Here's what
I did.  GENTLY fold in any gf food coloring of chose (we used all the colors)
to the already mixed bread (mixed in our kitchenAid mixer).  Try not to
change the complete color of the dough, but only streaks of color. Then place
into bread machine or let it raise and cook as usual in oven.

Give it a try.

Steve (from Boston) Bourque