Recessive yellow is the dilute of recessive red, both are striking colours in the showpen and in the aviary.
Recessive yellow/red is a colour which masks most other colours. Before the juvenile moult the flights are very whitish and the overall body colour is not as strong. As the bird grows in new feathers they are a deeper shade of yellow/red. When the bird reaches five or six years of age it starts to go whitish in the flights once again, almost as if it cannot cover up the underlyng colour.
The yellows are often not as strong a colour as the reds, however in the showpen a weaker colour yellow seems to get by whilst a red with weak or poor colour tail [termed plumy tail] is heavily penalised .
Below are a few I have had the chance to photograph.