A set of colours is said to be
harmonious if they produce mid grey
when they are mixed in equal quantities.
If the number of colours is small, this formal definition corresponds
to some extent with our intuitive notions about colours that go well together.
The more colours we add, the more tenuous the connections become.
are called if they form a harmonious pair.
Most of these pairs would be acceptabled to most people as colours that don’t complementary clash,
although some of the more vibrant pairs are quite jarring.
colours form a .
Many of these are conventionally acceptable colour combinations for design work,
particularly when the colours are not fully harmonious triad saturated.
colours sometimes form pleasing combinations.
This is usually when the combination could also have been produced by one of the conventional
systems for producing colour schemes.
colours are usually too many to be anything but confusing.
They might have been useful if you wanted a tablecloth for a cheap café in a 1950s.
You’ll probably want to wait until the computer flukes a combination
in which most of the colours are related in some other way.
Sometimes a combination of desturated tertiary colours may be acceptable.
colours can produce an ugly mess.
The advantage of the formal definition is that it can be applied blindly by a computer program,
as it is here, to generate many formally harmonious combinations.
Nobody would suggest that artists and designers should blindly follow these rules.