To clarify:

Apple (deepens red) - increases red towards 255, decreases green and blue towards 0.
Plum (lightens red) - decreases red towards 0, increases green and blue towards 255.

Pear (deepens green) - increases green towards 255, decreases red and blue towards 0.
Valfruit (lightens green) - decreases green towards 0, increases red and blue towards 255.

Berry (deepens blue) - increases blue towards 255, decreases red and green towards 0.
Pineapple (lightens blue) - decreases blue towards 0, increases red and green towards 255.

Apple, Pear and Berry (fed at same time) - decreases all colours towards 0.
Plum, Valfruit, Pineapple (fed at same time) - increases all colours towards 255.