It’s no secret that my favorite earth yellow is Daniel Smith’s Monte Amiata Natural Sienna (PBr7). But I also like a yellow ochre; for example, Holbein’s Yellow Ochre (PY42). They’re so similar that I wouldn’t want to have both in my palette at the same time, so which should I choose? Which is better in which situation?

Comparison in Various Situations
Yellow Ochres vary quite a bit, so bear in mind that these conclusions mainly have to do with this specific Holbein Yellow Ochre.
Hue
These two colors have an almost identical hue!
It’s no surprise that I was drawn to this one, since the hue is almost identical to MANS: very cheerful and yellowy, more goldenrod than brown.
Similarly, Daniel Smith’s Monte Amiata Natural Sienna (MANS) is the yellowest version of the traditional sienna/brown pigment PBr7.
Winner: Tie.
Usefulness
Sunrise/Sunset Skies
Both of these colors can be used in dilute to add a bit of yellow to skies, because they resist going green more than a typical yellow would. However, MANS resists turning green even more than Yellow Ochre does, and it dilutes to just as nice a yellow, so it’s especially great for this purpose.
Earth Tones
MANS looks browner in masstone so can be more versatile for various earth tone use cases (dirt, etc.), and it has nice gentle granulation.
Winner: Personally, I find MANS more useful and versatile.
Opacity
This is one of the main differences between the two colors. MANS is transparent, YO is opaque/semi-opaque. I find that I sometimes want an opaque color for things like clouds and mountain faces, to give them a sort of visual heft. It’s also better in foreground layers where you may need to cover something up. On the other hand, being transparent, MANS glazes better and mixes more completely.
Winner: It depends.
Granulation
MANS is gently granulating. This particular YO is non-granulating; some versions do granulate. Neither is better or worse, just depends on what you want. Granulation can give a textured appearance which is nice in mixed foliage greens and clouds, but sometimes a flat appearance is desired.
Winner: It depends.
Texture
This is a nitpicky little issue, but I have found that YO is texturally nicer in the pan – MANS has a tendency to form hard peaks and valleys, and YO doesn’t.
Winner: Yellow Ochre.
Color Mixes
Transparent Brown Oxide


The MANS mix looks more integrated, while in the YO mix, the TBO granulation floats to the top, giving it a “cinnamon dusted creme brulee” appearance.
Quinacridone Coral


I found the MANS mixes to be fiery and luminous, and the YO mixes to be more subtly pastel-ish. Of course, the quality of the light in the two images could also be affecting my memory.
Deep Scarlet


I had an easier time getting luminous mixes from the MANS, and heavier, darker, more chromatic mixes from the YO.
Quinacridone Magenta


Again, tMANS seems to lend itself better to diluted, transparent mixes, while the YO seems to lend itself better to darker and more muted mixes.
Cerulean


The MANS mixes mix more to a gray, while the YO keeps itself more separate, fading to a background gold with floating blue granulation on top.
Conclusion
The two colors have slightly different strengths. MANS lends itself better to luminous brights and glazes, while YO is easier to get deep and high-chroma for heavy, deep, intense colors. They are similar enough, however, to be more or less interchangeable in most scenarios. I feel that in general, MANS works better for my style of painting.