Creating a versatile colour palette

There has been an empty half pan in my palette for weeks and it's starting to bug me. The colour that was there before was Cadmium Yellow, an opaque colour that has very limited use for me. Before that, it was Phthalo Green. And now it's empty.

I've been thinking of what colour to add to my palette to make it more versatile. The colour that I have in this set has largely remained the same since I first got it in 2013. That was 5 years ago. I've been wanting swap out some colours but there's still a lot of paint in those 15ml tubes that I have. I reckon my supply of Quinacridone Red and Quinacridone Magenta can probably last another 5 years. Or maybe I haven't been painting enough.

What I mean by a versatile palette is, I want to have a palette that can mix any colour that I can think of.

There are different schools of thought when it comes to choosing colours.

One way is to choose colours around the colour wheel. That way, you'll have the primary as well as secondary colours.

The second way is to choose warm and cool versions of primary colours. This method is more common based on suggestions from watercolour forums online. This is also the method that I used when I picked colours for this palette.

The advantage of the warm/cool method is you get primary colours, and with them you can mix any secondary colours. Secondary colours can't be used to create primary colours or other secondary colours so their mixing potential is limited.

There's no such thing as perfect primary colours, which is what there are so many different yellow, reds and blues available from paint makers. Some don't even consider reds as primary colours, but I shall leave that to another discussion.

The thing is, even primary colours have their own characteristics and limitations.

If you use the wrong red and blue, you won't get a beautiful purple. Shown in the picture above on the left is a mix of Transparent Pyrrol Orange and Phthalo Blue. The result is a somewhat lackluster mix. When I switch to using Permanent Alizarin Crimson and French Ultramarine, the vibrant purple starts to show. Not satisfied, I switch to using Quinacridone Rose and French Ultramarine and manged to get a beautiful almost glowing purple.

Same thing when it comes to mixing orange. To get a vibrant orange, you have to start with warm yellows and warm reds. A cool yellow and cool red are not able to produce that bright warm fiery orange.

That's why it may be good to include several primary colours.

In theory, you're supposed to be able to mix any other colour from just three primary colours. But there's no such thing as a perfect primary colour. So each set of primary colour has its own limitation. So in order to create a more versatile palette, you just have to include more sets of primary colours. 2 sets of yellow, red and blues will be able to produce more colour mixes compared to 1 set. And 3 sets will produce more than 2 sets.

So in the current palette that I have right now, I've three yellows (Lemon Yellow, New Gamboge and Yellow Ochre), three blues (Phthalo Blue, French Ultramarine and Cerulean Blue Chromium) and two reds (Quinacridone Red and Quinacridone Magenta). So I'm seriously thinking of added another red to it. My choices are Transparent Pyrrol Orange, Quinacridone Rose or Quinacridone Liliac.

The non-primary colours that I have are Sap Green, Burnt Sienna, Permanent Brown. I use a lot of greens so not having to mix greens saves me time. With the earth tones, I can add them to French Ultramarine for a beautiful gray. But having two earth tones seems redundant, so I'm likely to drop Permanent Brown.

If I drop Permanent Brown, I'll have another open slot. So perhaps I could add red, or maybe add another yellow, perhaps Hansa Yellow Medium.

If you have difficulty choosing colours. You can create a colour chart using your existing colours. With a colour chart, you can tell at a glance what colours you're missing. For example with the Kremer Pigments colour charge above, I could tell that I'm missing vibrant purples. So to make a more versatile palette, I would need to add a cool red and a warm blue. In this case maybe a cool red since I don't see how a French Ultramarine can be warmer than the Cobalt Blue Dark.

Or maybe I should just leave that half pan empty. Maybe I don't need so many colours.