According to this chart:
Dalamud Red --> Rolanberry Red requires O'ghomoro Berries.
Dalamud Red (127, 31, 31)
Rolanberry Red (95,41,47)
O'ghomoro Berries (-5, -5, 5) so feed it the berries until it gives you the "beginning to grow new feathers" message. You only want to see this message once to indicate a color change.
Regal Purple --> Rolanberry Red requires Apples. According to the simulator, you want to feed it about 5 apples.
Regal Purple (103, 55, 87)
Rolanberry Red (95,41,47)
Apple (5,-5,-5) so same thing with the berries, you want to give it the apples for the "beginning to grow new feathers" message. You want to see this message twice.