This is ordinary color genetic.
Color genetic line of the blue mask betta fish are blue , steel blue and green.
Blue mask

Steel blue mask

Green mask
Yeah! you can matching blue+blue ,blue+steel blue , blue+green and steel blue + green.
All of the matching plan above , their children will be blue , steel blue and green. It is the same result.
Tips:
If you want to get mostly of their children to be blue, matching the blue with the blue and inbreed again.
The other colors genetic will be posted soon.