You can cold steep carafa and use that to add color, or cold steep the grains you mention, leaving out the pils malt. With the pils you have to do a mash, with standard steeping grains the temperature is much less important and since you're just trying to add color I would skip mashing.
If you are trying to minimize roast flavors you can still use carafa, just grind it as usual, put it in a french press with some cold water, let it sit over night, boil it briefly, then add it to the beer.
If you are using the same grains as in the recipe, then I'd do a warm steep of 30 minutes or so, boil briefly, and add it to the beer. I haven't done it, but I can't think of a reason it won't work.