3 different recipes. Brands sell different pigment mixtures under this name, so they won't all look or mix alike. Compare the pigments below; the most common is PB29 Ultramarine Blue.
Who makes it
PB29 Ultramarine Blue3
- Langridge Professional Oil Colour Kings BluePW6 PB29LF I OpaqueSeries 240 ml tube · 110 ml tube · 300 ml tube · 1000 ml tin · 4000 ml tinAbout Langridge
PB15 Phthalo Blue + PB29 Ultramarine Blue1
- Williamsburg Handmade Oil Colors No. 6000813PW6 PB29 PB15:3LF I OpaqueSeries 337 ml tube · 150 ml tube · 8 fl oz can* · 16 fl oz can*About Williamsburg
PB28 Cobalt Blue1
- Rembrandt Artists' Oil Colour No. 517
Sizes are the ones each line is sold in; marks a size only some colors come in. Check the store for a particular color.