Purchase 1 pint of color for every 2 gallons of part A.
Mix the color pack into the A part before adding the B part.
For multiple cans of A, pour them all into a clean 5 gallon bucket, add color pack(s), mix to consistant color, then, in a separate container, add the needed A part with the correct amount of B. Mix and apply immediately.
Final mix ratio will be 1 gal 8 oz of pigmented A to 1/2 gallon B