i must say the first picture is a girl and the 2nd pic is a boy..
im not good with mutations but here goes... yellow face type 2 clearwing violet?? and yellow face type 2 clearwing skyblue?
My first assumption was that they are both girls. both are clearflight, one has blotching/patches on the front(dominant?) or are they just considered clearflight pied. They came from the same clutch I know and are very similar. the grey seems to have white feathers and the blue seems to have yellow tint to them. in the picture the grey looks to have yellow tint but it was taken on my camera phone.
Yellow face opaline clearflight pied grey (male I think). Although he looks mauve the colour of the cheek patches show that his mutation is grey
Yellow face opaline dominant pied sky blue male
As they are siblings they could both be dominant pieds and the first one is just not showing the usual clear areas on the front. A photo of the parents would probably show which mutations are possible, and as opaline is a sex linked mutation the mother's mutation could help identify the sex of the chicks