They look really really unnatural. You could achieve a similar color distinction by making them bright yellow.
There's a lot of yellowish ants, like Lasius flavus (yellow meadow ant):
There's also some green ants, like Oecophylla smaragdina (asian weaver ant):
There's even some with color patterns, like certain versions of Camponotus nicobarensis, this could look good even with unnatural colors such as purple, blue or cyan.
Another way to do it would be to apply color only to the heads like Camponotus singularis does, maybe combined with a dot-patter on the gaster (abdomen) as in the picture above.
There's a lot of yellowish ants, like Lasius flavus (yellow meadow ant):
There's also some green ants, like Oecophylla smaragdina (asian weaver ant):
There's even some with color patterns, like certain versions of Camponotus nicobarensis, this could look good even with unnatural colors such as purple, blue or cyan.
Another way to do it would be to apply color only to the heads like Camponotus singularis does, maybe combined with a dot-patter on the gaster (abdomen) as in the picture above.