There is no way to match the color without painting all the steps. You could just paint the risers (or front of the step) to make it look uniform from the street however, I would not want paint on the srface of the treads.
It only takes one form board to hold one step; it could be wedged in between the curbs and kickers of 2 X 4 could be angled out over the curb to a stake on each side. You will probably use bag mix and place it by hand which would be easier to hold with the form. Just mix the concrete rather dry and crumbly, place it in the form, tap on the face of the form to remove any air bubbles and trowel the top with a wooden block.