Janus said:
..is that the type of colour mixing we do is the subtractive method.
Yep. Each time paints are mixed it subtracts colour from the light shining onto it. This is most obvious in a mixture of two colours - that aren't necessarily that dark to begin with - resulting in a dark neutral, nearly black in some cases.
In any complementary mix the resulting grey/near-grey is noticeably darker that either of the two starting paints.
Janus said:
That is, when we look at something blue under white light, all wave lengths except the blue are reflected from the object into our eyes.
In simple terms, yes.
It's not as simple as that in practice (yellow for example also reflects most or all of the orange and red light too, as well as green).
Janus said:
Chroma, hue and saturation are all things that have faded after 10 years+ out of the printing trade, so I admit I know next to nothing about it.
There are three dimensions to colour, with varied names; the most useful for painters are probably hue, chroma and value.
Hue is the basic colour 'family' - yellow, orange, red.
Chroma is the intensity or purity of a colour - high in chroma = brilliant, low in chroma = duller or greyer.
Value is simply how light or dark something is - dark = low value, light = high value.
To give a fun example: coffee with milk in it is orange in hue (!), very low in chroma and high in value. Coffee without milk in it is also orange, but low in chroma and very low in value obviously (in practice it can actually be black to our eyes).
Janus said:
Question(s); Neutrals - are these a grey, or just something between the two colours?
In artists' parlance 'neutrals' can refer to dull colours generally or near-greys (where there is still some visible hue).
An actual neutral is pure grey; white and black are also fully neutral and can be thought of as the start and end of the range of neutral greys.
Important point to mention here is that white paint and black paint are generally neutral,
but a mixture of them won't be. Almost all black + white mixtures are noticeably blueish. If you need to mix a neutral grey a little bit of an earth colour is usually added to make the mixture completely neutral (this is how commercial neutral greys are made).
Janus said:
Blue + Yellow - I asked a kindergarten child about this, and "green!" was the answer. There such a thing as a neutral green?
It's a bit of a misleading way of saying it but yes, in a way.
Usually when this is said it refers to something where there's no obvious leaning toward the hues on either side. So in the case of green it wouldn't be yellowish or blueish, for orange it wouldn't be yellowish or reddish, for yellow it wouldn't be greenish or orangey, etc.
Janus said:
And a thought - would it be simpler for us new types just to make a crude colour wheel from our paint set? Just as a learning effort, until we get a decent 'mixing' colour wheel?
It is a very good idea for any painter to make a lot of mixtures from the palette they use, to learn hands-on what the paints do. Interpreting the results and putting them into context takes more study.
But it's useful to pick up directly from what the mixtures actually give that paints don't necessarily mix like theory says they 'should'. A violet-blue and a light, clear yellow for example can be directly opposite each other on a colour wheel, and yet they
always mix green... theory says they should mix grey or something close.
Einion
