Conference posters are visual. I’ve spent a lot of time talking about arrangement and shape, but let’s turn to another element: the colour.
There are a couple of tricks you can use to maximize the effect of colour. This one is well known to those who work with colour, but many academics might not have thought about it unless they're into Trading Spaces.
The Slide:ology blog pointed out how many movie posters are built around blue and orange. Then, the Into the Abyss blog pointed out that it’s not just the posters getting this treatment.
And I can’t help but notice the colours for the website powering this blog as I type this...
The idea here is that blue and orange are complementary colours, so that a small patch of one will “pop” against the other. Purple and yellow are complementary colours, and so are red and green.
This fits nicely with one of my suggested “rules of two,” which is to limit yourself to two colours. By making sure those two colours are complementary, you’re going to maximize their impact.
Blue and orange may be becoming a cliché in movie posters, but probably few makers of conference posters have twigged to this strategy yet. Make use of it before everyone else catches on.
Purple and yellow can work, too, if you are careful with the yellow. Because yellow is a light colour, it is sometimes hard to distinguish against white, which often makes up a large portion of a conference poster.
Red and green are probably the most tricky to use, and not just because people associate those colours with Christmas (as the Slide:ology post points out). Using red and green run the risk of confusing the not-so-small number of people (mostly men) who are red / green colour blind. It’s particularly tempting to use red and green to colour code a graph that needs more than two colours, because they are primary colours. Be very careful with them.
The two colours are that are the most opposite, the most complementary, the most striking, are still black and white. When in doubt, stick with those. They’re hard to screw up.