There are just 2 base colors in love birds, Green Series and Blue Series.  Blue series can be broken down into blue(formerly known as dutch blue), seagreen, and whitefaced.   Seagreen and whitefaced are all considered blue series birds. 

 

1. Green Series

2. Blue Series

 a) blue

 b) seagreen

 c) whitefaced

 

Blue bird x Whitefaced Bird = 100% Seagreen Babies

Whitefaced bird x Whitefaced Bird = 100% Whitefaced Babies

Blue bird x Blue Bird = 100% Blue babies

Green bird x Blue Bird = 100% Green Babies/split to blue  

Green bird x Seagreen Bird = 50% Green Babies/split to blue and 50% split to WF

Green bird x WF Bird = 100% Green Babies/split to WF

 

Green is always dominant over blue.   Many green birds are split to some type of  blue nowadays. There is no way to tell visually if a green series bird is split to blue, the only way to know is if you have the bird's pedigree, the genetics of the parents, or breed the bird and look at the offspring. Sex-linked mutations such as Australian Cinnamon, Opaline, American Cinnamon, and Ino also come either in the Green or Blue Series. These mutations may not look green or blue at all but are always either green series or blue series birds.