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?
Phthalo Green (PG7) is a super vivid, deep, cool (blue-toned) green. To me, it feels like a glowing, hidden pond deep in the rainforest. It is incredibly bright; some folks find it “unnatural” so it may be most useful as a mixer than a natural landscape color.
(There’s another Phthalo Green – PG36 – which is more yellow-toned, that I’ll discuss in a future post.)
Like all the Phthalos, this green is extremely strong and staining. Some people don’t like that about it, and it does have a tendency to overwhelm mixes with weaker colors… but I love it! I’m lazy and I love a color that doesn’t make me work. I just have to make sure my palette is full of similarly vivid colors that can hold their own.