I'm working on a map showing on which days garbage is collected in different areas. That means it's pretty tempting to colour code each zone with a different colour representing a day of the week.
Are there any conventions to follow? Is 7 colours too many?
Here's what it looks like at the moment:
My colours so far follow the rainbow from Monday to Friday (red, yellow, green, blue, purple) then light grey and dark gray for Saturday and Sunday.
Here are the numerical values in the image, for interest. (CartoCSS, Tilemill.)
@s: 60%;
@l: 70%;
@monday: hsl( 0, @s, @l);
@tuesday: hsl( 60, @s, @l);
@wednesday: hsl(110, @s, @l);
@thursday: hsl(200, @s, @l);
@friday: hsl(250, @s, 80%);
@saturday: hsl( 0, 0, 70%);
@sunday: hsl( 0, 0, 70%);
So the weekdays are all the same luminosity and saturation except Friday, which I found seemed too dark, for some reason. I originally spaced the hues equally around the spectrum, but found that there were two blues too similar, and several of the colours just weren't attractive.