In this Color Comparison, I’ll compare two similar yellows that I love: Imidazolone Lemon (PY175) and Imidazolone Yellow (PY154). Both are very bold, lightfast yellows that can be used as a primary yellow in a palette. Either one of them, if you showed it to me, I would be like “yup that’s the platonic ideal of yellow,” but next to each other I can see how they are actually kind of different.
- PY175 Lemon is more green-toned.
- PY154 Yellow is more warm or slightly orange-toned, and can get a bit darker.
If I were to name each of these concentrations, I would call them:
- PY175: Highlighter, Lemon, Lemonade, Lemon Yogurt
- PY154: School Bus, Yield Sign, Sunshine, Butter
Some more things that can’t be seen in the scans:
- I found PY154 a bit harder to rewet (though perhaps it’s because my dry lump was older).
- PY154 seemed streakier in mixes (again perhaps due to being dryer)
- PY154 had a very faint chemical smell when wet.
Getting from one to the other
I found that PY175 Lemon could be mixed with Permanent Yellow Deep (PY110) to get a convincing PY154 hue. But I couldn’t figure a good way to get to PY175 from PY154.
Color Mixes
Naples Yellow Deep (PBr24)
These don’t appear too different in scans, especially in the middle or golder end. The Naples Yellow Deep serves a similar function to PY110 of turning the PY175 into a warmer yellow.
Gold Ochre (PY43)
Similar to Naples Yellow Deep.
Quin Magenta (PR122)
The PY154 seems to make more satisfactory reds and oranges, though these swatches aren’t particularly comparable.
Quin Red (PV19)
Quin Coral
Carbazole Violet (PV23)
The PY175 mixes almost a neutral gray where the mixes with PY154 are more browish. Either way I think this looks like mud.
Ultramarine Blue (PB29)
Phthalo Blue Green Shade (PB15)
Here’s a case where I did the swatches on the same day, on the same paper. This allowed me to see pretty clearly that they were quite similar (when mixed with more blue), but the PY175 green mixes had a cooler, crisper look while the PY154 yellow-green almost looks grayish in comparison. PY154 also was quite streaky while the PY175 made smooth mixes.
Phthalo Green Yellow Shade (PG36)
The Lemon mixes are much more “neon-y” and jump off the page with boldness.
Color Wheels
Here’s a primary color wheel where I have just changed the yellow.
Something I found interesting is that the PY175 mixes seemed to have more texture as well as being a bit cooler (both of these were done on Canson XL paper). It’s possible I just did something different with my brushwork.
I actually found the warm mixes not too terribly different here but I see the biggest difference in the yellow-green, where the PY175 yellow-green is a very springy lime where the PY154 yellow-green is more avocado-y.
Conclusion
This is a pretty inconsequential decision, particularly in my palette context, since I already have a lot of other yellows. A basic versatile yellow is said to be a palette staple, but to be honest, I use this sort of plain, bold yellow surprisingly infrequently. I usually mix greens with PY150 or PY129, and warm oranges with PY110. Yellow tones in skies usually come from an earth yellow such as gold ochre, Naples Yellow Deep, or Raw Sienna. So for me, this color is primarily for situations where a pop yellow is called for.
Purely on aesthetic grounds of which color I like in swatches, I’d probably go with PY154. I prefer warmer yellows, which make me feel happy. PY175 looks a little “highlighter.”
Experientially, though, I enjoyed the texture and smoothness of PY175.
PY175 is also more unique, both in terms of being less mixable, and in my particularly palette context (where I use a lot of warm/earthy/orangey yellows).
Because neither is the clear winner, I’m kind of wondering if I should ditch them both and go with something sort of in between like Azo Yellow.