Today, I tried mixing five different yellow paints with Golden’s Phthalo Blue (Green Shade [or, “GS”]) acrylic paint, making spectrums of color from yellow to blue. I’ve had issues for a very long time with trying to mix realistic greens — luckily, it’s a bit easier in acrylics, than in watercolors! (At least, my first try at this was in watercolors — I now have more experience, which may make the difference.)
I now recognize at least part of why it has been difficult for me to get a green that looks like it could occur in reality: a “greener” yellow will not necessarily produce a more intense and realistic green color. Color “impurities” — what other colors exist within a paint — matter, that is. I have a feeling they’re more essential than might be guessed.
UPDATE: I’ve decided it will be more helpful than not to post the photo of my work, although the rest of this entry assumes I have not.
UPDATE II: I’ve deleted the griping about my inability to properly adjust the photo below. Just know that it’s an imperfect image of the real thing. In particular, the entire PY3 column is much brighter in reality, and pretty much all of the dark blue-greens are much more vivid than I could make them.
For those who know about pigment codes already (PY=”Pigment Yellow,” PB=”Pigment Blue”) and want to skip to the point, PY74 (Liquitex Yellow Medium Azo), a bright banana-hue yellow, makes the most gorgeous and usable greens with Phthalo Blue (GS) alone, out of all the pigments I tried (PY3 [Yellow Light Hansa], PY74 [Yellow Medium Azo], PY83 [Diarylide Yellow], PY139 [Indian Yellow], and PY42 [Yellow Oxide] — all of these are Liquitex brand, except for Diarylide Yellow, which is Golden brand).
PY139 (Indian Yellow) mixed with PY74 (Yellow Medium Azo) to brighten it, plus Phthalo Blue (GS) and Ultramarine Blue (Red Shade, or “RS”), give the closest approximation to lush greenery I’ve been able to achieve by mixing single-pigment colors. At least — I believe it’s Liquitex’s Indian Yellow (PY139) that I used in that sample…it may have been PY83, Golden’s Diarylide Yellow.
I can’t be certain: PY139 and PY83 are very similar in hue. They just mix a little differently, with PY139 being just slightly bluer, or cooler, in my mixes.
I’ve been trying — for years — to avoid using known toxic substances in my art; however, it’s very obvious to me now, why some people use known less-safe pigments. Sometimes, that is, it’s easier (and in the long run, cheaper) than trying to find a suitable replacement, and I can see people saying that good hygiene should be a studio essential, anyway (although it often isn’t followed). Finding a replacement for cadmium yellow and cadmium red has taken up a good deal of my time.
Even though I don’t know what’s in Liquitex’s Cadmium-Free Heavy Body paints (which were made to approximate the behavior, hue, and opacity of the cadmium pigments), I might want to try them — and just follow the safety protocol given. The hazards of cadmium (not just to myself, but in the environment, where it may bioaccumulate and poison someone or something down the line) just feel too severe. As time goes on, we do find better and safer colors — I know, because I’ve been looking for them (and often finding them), for years.
What I can do right now, and not totally fail at; is describe the colors I experimented with today (for you to look at in reality, if you have the same paints), and note — at least, for myself — some broad ideas about which paints to use, when.
PY3, or Hansa Yellow Light (you will often see these words on the paints using this pigment, but not in any predictable order: I just like calling it Hansa Yellow Light instead of Yellow Light Hansa), is a blue-leaning, very intense, very light-colored pigment. Mixed with Phthalo Blue (GS), it produces a series of vivid greens that all lean blue. Because they lean so far blue, without additional color to alter the mixture, we end up looking at a green which is usable in high-key paintings (that is, they have a lot of vividness), but the color is not highly realistic.
PY74, or Yellow Medium Azo, is a midtone yellow which reminds me of banana peel in hue. This yellow produced the most realistic greens when combined with Phthalo Blue (GS). If I had to choose only one yellow to have, and I had to stick with Phthalo Blue (GS), it would be this yellow. The greens are more midrange, looking as though they could be chlorophyll; however, I would shift to a different mixture for shadow areas of trees, and the like. More on this, later.
PY83, or Diarylide Yellow, is a beautiful pigment, almost mango-colored. It leans more orange than Yellow Medium Azo, and as a consequence, when mixed with Phthalo Blue (GS), the mixture is increasingly muddied, the more yellow is included. However, for some reason, I got a really nice, deep and rich green out of it when more Phthalo Blue (GS) was added; though those proportions produce a mixture which is very dark in value. (“Value” is the lightness or darkness of a color, shade, or tint, regardless of which of those, it is.)
PY139, or Indian Yellow (Liquitex), is close to Diarylide Yellow when painted straight out of the tube; however, it is just a slight bit duller, whereas Diarylide Yellow is more luminous — I’m not sure why. Mixing Indian Yellow with Phthalo Blue (GS) produces a very nice dull green very quickly and easily. This was the first mixture I painted out, and it shocked me how quickly the mixture turned to a mid-green (although Phthalo Blue is known for its ability to tint mixtures very quickly and strongly). Consequently, I did not know what to do, and missed out on exploring the more blue-green avenues of this mixture. The mid-green I immediately got, however, is bluer and slightly clearer (less muddy and less reddish) than Diarylide Yellow plus the same blue. That might be desired; it might not be.
PY42, or Yellow Oxide (Liquitex) did surprise me with the range of greens I was able to obtain by mixing it with Phthalo Blue (GS). This is an earth tone, essentially what other people may call a yellow ochre (or ocher). Particularly, mixing Phthalo Blue (GS) with a little Yellow Oxide, makes a very dark and rich green — but in low lighting, one may not be able to clearly tell that it is green. This mixture would be good for shadows. I probably wouldn’t use this mixture as more yellow is added, as it tends to look just like a muddy dull yellow.
For a clearer green in the light-valued ranges, I’d lean toward Yellow Medium Azo and alter the color from there, either using a different blue, or adding bits of other colors (like an orange-leaning yellow) to tone down what is essentially a bright, garlic-sprout greenish yellow.
I’ll add to what I mentioned at the beginning of this post: the nicest greens — indeed, the nicest colors — I’ve gotten have not been simple two-color mixtures. In any case, it’s not possible or desirable to keep all paints from interacting with each other on the palette. A little bit of contamination, in my experience, has had a tendency to increase color harmony in the piece by introducing complexity and relations between different areas with the same color.
As well, it may be in some cases, enough to note a masstone (what is the hue? [yellow, blue, etc.]) and an overtone (what is the major color that modifies the hue? [orange modifying yellow, red modifying blue, green modifying blue, etc.]), plus temperature (does the color lean hot [violet/red/orange] or cool [yellow/green/blue]?) in a paint — rather than seeking out one pigment or another by name. I’ve started to try and get single-pigment paints because I’ve read they mix more reliably than what are called, “convenience mixtures,” or pre-mixed colors, like Hooker’s Green Hue Permanent.
Of course, that means I’ve had to find out for myself, how to mix a decent green.
The major exception to looking just at hue, overtone, and temperature, which I can think of, has to do with transparency: a transparent pigment will likely show brush strokes, whereas I don’t think this is a problem so much, with opaque pigments (I just noticed the brushstroke thing, today).
I found a deep shaded-grass green through using an orange-leaning yellow (like Diarylide or Indian Yellow), plus a little Yellow Medium Azo to punch up the brightness of the yellow. I then combined that with Phthalo Blue (GS) and a little Ultramarine Blue (RS). Adding too much Ultramarine will start pulling you off into indigo, but otherwise, it’s possible to get a very deep, lush green.
There’s likely something going on with the violet in the Ultramarine, and the orange in either of the orange-leaning yellows. I can hypothesize that they make a chromatic gray which deepens the tone and allows the green to come through more clearly (though magenta/violet and orange are not really “opposites” — they both sit to one side or another of red on a painter’s color wheel — which is, actually, opposite of green on the color wheel [which probably matters: red cancels out green to make a chromatic grey])…but honestly, I don’t have a spectroscope, and it isn’t really possible to separate out the orange from the yellow, and the violet/magenta from the Ultramarine.