On my computer monitor, in the first two pictures the ceres of both birds appear to be a smooth pinkish/purple color which indicates they are both male.
However, in the next three pictures the ceres appear much lighter...
Lighting and angle makes a difference when determining gender.
What color do the ceres appear to be to you?
If you post full sized full frontal pictures of each of their ceres taken in natural light - No flash/no direct sunlight that would be helpful.