I divided the dough into six roughly equal portions, and scrounged around the kitchen for bowls. I came up one short, so purple was mixed on a small plate instead.
I rolled each color out, using copious amounts of powdered sugar so the dough wouldn't stick to the rolling pin or parchment paper. I think this step would have gone more smoothly if I'd actually let the dough rest in the fridge for 1-2 hours, instead of the half hour it was in there. My boys vehemently disagree, and think any delay in rolling out the dough is silly. They may or may not be sort of impatient when it comes to baking.
We stacked the sheets as we rolled each color out.
There was some disagreement as to the order. My older son insisted that blue comes before green, not after. I countered with ROY G BIV, and he thought I was silly and still wrong, but let me have my way. He then helpfully pointed out that real rainbows have two purple colors, not just one. Smart kid.
Once I had the layers all stacked, I lightly rolled them out all together, as I was worried the stack was too thick to roll into a log. Once rolled out -- this helpfully smashed the layers together a bit too -- we carefully rolled into a cookie dough log.
Then the log went back into the fridge. Cue more groaning from the boys. I cleaned up around the kitchen while the boys ate the scraps of dough from the color mixing bowls. Powdered sugar makes a terrible mess, and I've been trying to clean up after my baking more quickly so as not to exasperate my husband. I gave into the boys' harassment after half an hour or so, and got ready to put the first batch in the oven.
The slicing would have been easier if I'd waited until the dough was colder. I put the dough log back into the fridge between batches, and it was easier to slice each time. As it was, I had to clean off the knife blade after every slice. I was a bit disappointed in the spiral of colors in the raw dough. The colors ran into each other a bit more than I wanted them too. When they came out of the oven though, they looked great!
I think the addition of the coloring gel, plus the almond extract, made the dough a bit stickier than it otherwise would be. I didn't want to add flour out of fear that it would make the dough too tough though. When we make these cookies without the extra color, they hardly spread at all -- a real positive when trying for different shapes with cookie cutters. These cookies spread a lot.
The boys are thrilled with them though, and there was much wailing and gnashing of teeth when I told them they had to eat dinner before having cookies.