Belle is typically in her blue dress at CRT. Actually my DD thought she was underdressed and wondered why Belle didn't have her ball gown. However, be aware that Cinderella is the only guarantee at CRT. Though she is typically there I don't think she is ALWAYS there.
Our picture at Akershus was with Belle in the gold dress. I think she is almost always the princess for the Akershus pircutre palace.
FWIW, the dress and the identity of the picture package princess was the only difference in the Princesses at both meals. We saw Snow White, Belle, Cinderella, Aurora, and Ariel at both CRT and Akershus.