What’s the difference between Phthalo Green (Blue Shade) and Phthalo Green (Yellow Shade)?

The two Phthalo Greens, Blue Shade and Yellow Shade, are made from different pigments (PG7 and PG36, respectively), but they share many properties. They are both very strong and staining, transparent, bold greens. They are similar enough that you probably don’t need both on the same palette, so which should you choose?

Hue Comparison

The basic difference is of course that Blue Shade is more blue-toned, and Yellow Shade is more yellow-toned. I would describe Yellow Shade as being a middle green rather than a very yellowy green.

Both would need to be mixed in order to make natural-looking greens for realistic landscapes. While I like these colors, I understand what people mean when they say they’re artificial-looking on their own: they are quite vibrant, and look more like my polyester down jacket than they do like real leaves. I don’t mind that, since I think it’s a lot easier to mute color than to embolden them, so I’d rather my base colors on my palette be brighter than life.

Landscape artists usually consider them mixers; you can mix naturalistic foliage greens by neutralizing and muting them with earth tones, oranges, and scarlets.

Let’s explore how they mix.

Color Mix Comparison

Hansa Yellow Light (PY3)

The PG7 mix looks more “glowing” in the cooler, greener mix, while PG36 looks more “glowing” in a slightly yellower mix. PG36 creates a more neon-looking, highlighter green.

Azo Yellow (PY151)

Similar to PY3 mixes, though they get darker in the greener end because the yellow is more transparent.

In real life, the PG36 mixes look slightly higher chroma overall, but in the scan they are about even.

As with PY3, I’m seeing more “glow” in the yellow-green mixes for PG36, and in the greener mixes for the PG.

Imidazolone Yellow (PY154)

The mixes with a middle yellow, such as PY154, are very similar. As you might expect, Blue Shade mixes have a slight coolness to them, even with yellow added, while Yellow Shade mixes are more intensely vibrant yellow-greens. The difference is subtle, though.

Hansa Yellow Medium (PY97)

Very similar to PY151 and PY154 etc mixes. As before, the PG36 mixes look higher-chroma in person, with the highest chroma mixes being mostly yellow.

Nickel Azo Yellow (PY150)

These are better landscape greens, at least for glowingly bright summer foliage. The NAY gives these mixes the warmth and depth of color that the PY154 mix lacks.

I especially like the Blue Shade mixes. To me, they achieve that sunshiney glow while still retaining that coolness that you want to imply a verdant, leafy glade.

The Yellow Shade mixes don’t impress me as much. The mostly-green mix is too neon for me, looking more like the PY154 mixes. The most-PY150 mixes look like unmixed Rich Green Gold. I find them a bit too “pickle juice.”

Alizarin Crimson Quinacridone (PV19)

More of an even, complementary gray made from Blue Shade; Yellow Shade always remains sort of a warm violet or brown.

Quinacridone Rose (PV19)

These are painted with DV Red Rose Deep, which is on the warm/red side for a Quin Rose, but still cooler/purpler/closer to magenta than Alizarin Crimson.

When it comes to the bluer Quin Rose, Yellow Shade is closer to being a complement and makes a fairly even gray; Blue Shade always makes kind of a deep indigo. (A bluer-toned Quin Rose, such as Daniel Smith’s, makes even more vivid blue/purple colors with PG7.)

I used more paint on the PG7 so it looks darker, but I think both can get approximately the same darkness.

Phthalo Blue GS (PB15:3)

Both make wonderful teals. I find these the hardest to tell apart. In theory, the Blue Shade teals should be more vibrant, the way the Yellow Shade yellow-greens are more vibrant, but honestly I think they are both equally good; if anything, I may prefer the unexpected brightness of the Yellow Shade teals better. (Daniel Smith agrees with me, since it uses PG36 in its wonderful Phthalo Turquoise mix!)

Cost Comparison

Blue Shade is a series 1 color, and Yellow Shade is a series 2 color. That means Blue Shade is consistently cheaper (at least within the same brand; the cost difference between brands may be more or less than the cost difference between series of the same brand.) I think this is why commercial mixes almost always use PG7, even where PG36 would seem to make more sense.

Conclusion

In terms of unmixed hue, I like Blue Shade better, but one would rarely use the unmixed hue (at least in naturalistic landscape painting), so this is one where the color mixes are crucial.

Yellow Shade:

• Makes more vibrant, nearly neon yellow-greens with a middle or cool yellow
• Neutralizes Quin Rose

Blue Shade:

• Reliably mixes a variety of balanced, cool/warm summery foliage greens with Nickel Azo Yellow
• Neutralizes Alizarin Crimson

Both make wonderful teals.

Winner: Probably Blue Shade? It’s cheaper and slightly easier to find, and the mixing difference between the two is nearly imperceptible. I like the Blue Shade better unmixed, though this is a subjective opinion. Yellow Shade might get the edge for spring palettes and bright bud greens, though Cobalt Turquoise is also an option.