A high contrast is going to be very, very bright yellow - but they do change as they mature, so it can be hard to really label them. The deeper the orange as a baby - the more bright sharp yellow they'll be as adults.
Sounds like you're also looking for a reduced pattern one as well.
Here's my boy - reduced pattern, but time will tell if he'll truly be "high contrast".
I think I know the soft yellow that you are referring to though.
![]()