Would be lavender with white barring. (as seen on your rooster)
Those barred/cuckoo birds *may* be split to lav.. aka carrying it hidden (only one copy of the lav gene).. but they are certainly not Lav cuckoo. You can breed them to otrher lav birds to test mate them IF desired. If carrying Lav will throw lav offspring when bred to lav.
The isabel roo is cuckoo (that's pretty!).. the hen.. looks just isabel, no cuckoo (from what I can see).. the sire should pass his barring to all his offspring.
Working with project colors can be quite the challenge.. also keeping them separate.. and also keeping all the genetic information straight.
Lovely birds.