Donald, bitone and bicolor refer to differences in the base color of the segments.
Bitone or a reverse bitone has lighter and darker shades of the same base color. Bitone, has the darker shade of the base color on the petals with the lighter shade on the sepals, reverse bitone has the darker shade on the sepals, lighter shade on the petals.
Bicolor is two different base colors, petals a darker base color than sepals would be bicolor. Sepals a darker base color than petals a reverse bicolor.
Happy Happy has a cream white base color on both sepals and petals so is not a bitone or bicolor.
I showed some examples in this ATP article.....
http://garden.org/ideas/view/C...
