Every brand makes it with the same pigments: PBr7 Natural Iron Oxide.
Who makes it
- Williamsburg Handmade Oil Colors No. 6000045PBr7LF I Semi-opaqueSeries 337 ml tube · 150 ml tube · 8 fl oz can* · 16 fl oz can*About Williamsburg
Sizes are the ones each line is sold in; marks a size only some colors come in. Check the store for a particular color.