Cut your boards twice as long as they are wide. Be sure to measure the board to get your measurement as a 1x6 board is not 6 inches wide.
Paint all of your boards with the black base coat. You will want to spray one side, allow it to dry, then flip your pieces over to paint the opposite side. Allow to dry for 24 hours before painting the color shift top coat.
Once your boards are all black, you can use the color shift top coat in the color of your choice.
Once again, paint one side, allow to dry, then flip over your pieces to paint the opposite side. Allow to cure for 24 hours.
Then you can add your middle lines as well as your circles to each domino one of three ways. First, you can use a round sponge brush and dip in the paint for the circles then freehand the lines with a paintbrush. Don't love the idea of freehand? Try cutting a stencil from vinyl on your Cricut and using the paint to fill that in. You can also just use the vinyl pieces on your dominoes if you have an outdoor vinyl. You can find a cut file for the dominoes I made here if you decide to use your Cricut machine.
Continue until you have added lines and circles to all of your domino pieces.