Some of the paints Bob used are not standard colours that you would find made by other brands. They are colours mixed specifically for Bob Ross Inc. Unlike many other brands of oil paint, BRI doesn't list on the tubes what pigments are used in making their colours. Nor do they list them on their website. Recently I was watching a YouTube video in which a painter mentioned an art supplies website (Blick Art Materials) that lists the pigments of every paint they sell. So I decided to check whether they sold Bob Ross paints... and they do. So here are what BRI's paint manufacturer uses to make each colour.
Titanium White is made from PW6 (Titanium White) pigment.
Midnight Black is actually a mix of PR83 (Alizarin Crimson) and PG7 (Phthalo Green).
Phthalo Green is made from PG7 (Phthalo Green).
Phthalo Blue is made from PB15:3 (Phthalo Blue).
Prussian Blue is made using PB27 (Antwerp Blue), which is a variant of the standard PB27 (Prussian Blue) pigment.
Van Dyke Brown is a mix of PBr7 (Burnt Umber) and PBk9 (Ivory Black). Gamblin 1980 Van Dyke Brown is made with the same pigments. Winsor & Newton's Artists Oil uses PBr7 (Burnt Sienna) and NBr8 (Van Dyke Brown) and their Winton VDB uses PBr7 (Burnt Umber), PR101 (Mars Orange), PBk7 (Lamp Black).
Dark Sienna is made with PBr7 (Burnt Sienna).
Mountain Mix is quite the cocktail of pigments. It uses the PB27 (Hooker’s Green) variant of Prussian Blue, PBr7 (Burnt Sienna), PBk9 (Ivory Black), PR83 (Alizarin Crimson) and PG7 (Phthalo Green).
Alizarin Crimson is unfortunately still made with PR83 (Alizarin Crimson) which is not lightfast. Other brands' "permanant" versions of Alizarin Crimson are made with PR177 (Anthraquinone Red), so I think I'll be switching to either W&N Winton or Gamblin 1980 when my BRI tube runs out.
Sap Green is a mix of PY42 (Mars Orange), PY83 (Diarylide Yellow 83) and PG7 (Phthalo Green). Most Sap Greens seem to be made by combining the Phthalo Blue pigment with a yellow pigment.
Cadmium Yellow Hue is made from the much less toxic PY74 (Hansa Yellow) pigment.
Indian Yellow is PY83 (Diarylide Yellow 83), as is Gamblin's "1980". W&N use PY139 (Isoindolinone Yellow) and PR101 (Red Iron Oxide).
Yellow Ochre is PY43 (Yellow Ochre).
Bright Red, which I always assumed was based on cadmium red, is actually a mix of PR255 (Coral Red)
and PR254 (Pyrrole Red).