Like the original better? You could paint extra smudges in darkblue with a paintbrush. Or you could even buy one on Etsy by twostringjane.
My tank is more of an ombre type technique.
Buy a white racer back tank top.
Wash it and leave it wet!
Put a piece of cardboard inside of the tank top so your paint does not run through.
Cover workspace with plenty of newspaper.
Find a water spray bottle and fill it with one table spoon of yellow fabric paint and 6 tablespoons of water. Shake well.
Spray the paint on the left side of your shirt until you can't spray anymore.
Rinse water bottle thoroughly and fill it with one table spoon of blue fabric paint and 6 tablespoons of water. Continue spraying on the right side of your shirt until you can't anymore.
Repeat these steps for darkblue and red.
Red left side of blue and darkblue right side of blue.
Leave to dry, you could speed this process up with a blow dryer. DON'T REMOVE THE CARDBOARD INSIDE!
When dry iron your top, then wash in washing machine (cold setting) to wash out excess fabric paint.