They are different. You get 2 types of YF: YF1 and YF2. The difference between them is basically that the yellow in a YF2 spreads through the whole body of the bird - making the blue looks more than a seagreen. In some cases the bird might look like a green bird, but when you look under the wing you woll see the blue colour. GF is a much richer yellow.
Creamface - very pale yellow almost a dirty white or a light butter milk look. The yellow stays on the face.
(I produced one of these birds. First time I had ever seen one. I really thought the poor bird had a dirty face. I took her indoors and started to "scrub" her head with soap when I noticed her tail had yellow in it. I felt SO bad that I tried to scrub the yellow out of her feathers.)
Yellowface - darker yellow again this yellow stays on the face.
Goldenface - dark yellow that "bleeds" into the body coloring. With some birds this "bleeding" can continue further down the body with each molt.