A mixture of two Arylide Yellows and Titanium Dioxide, Primary Yellow can be a semi transparent, utility mixer. 

Pigment Classification: Organic
Color Index Name: PY 175 / PW 6 / PY 74
Color Index Number: 11710 / 11738 / 77891
Chemical Description: Arylide Yellow 10G Arylide Yellow Titanium Dioxide Rutile
Opacity/Transparency: Semi-Transparent
Lightfastness Rating: II
Permanency: Very Good