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?
Color Spotlight: Phthalo Green Yellow Shade (PG36)
PGYS is a highly-staining, highly-transparent, classic grass or emerald green, more yellow than its brother Phthalo Green Blue Shade (PG7).
Color Spotlight: Phthalo Turquoise (PB16)
This is an automatic color of interest to me because I love teals and turquoises!