You know how important catching a person’s eye is. It can attract players to places they would never explore otherwise. It shows players a weapon that they may not have been able to find otherwise. There are many ways to draw a player’s gaze. One of those ways is to use contrasting colors in an otherwise bland scene. But color contrast isn’t just about eye catching.
The color wheel
So everything we see exists on our visible color spectrum with each color slowly blending into the next and becoming a new color. A natural occurrence of the color spectrum is a rainbow. A rainbow is seen by the human eye as several colors blending into each other from Red to Purple. The color wheel just places all of these colors in a perfect circle that links the red to the purple in order to restart the color sequence. Most color wheel diagrams consist of 12 colors containing the three primary colors that blend together to form three secondary colors and then all six of these blend with the one two next to them to create six tertiary colors. You can easily find an example of the color wheel by searching google.
The difference is black and white
Contrast is defined as the difference between two colors that appear next to each other. It is easy to notice when something black is on a white field, but how easy is it to tell when something black is on a purple field in comparison? With that in mind how much do you want that black object to stand out? If you want the object to just accent the scene then maybe the black on purple is a good idea, however if you want it to stand out then maybe the black on white is a better idea. High and low contrasts are both important in their own situations. You do not want to be bringing attention to something that doesn’t need attention and you don’t want to hide something that needs to be seen. So how do you find low contrast and high contrast color combinations? Take a look at a color wheel. Pick one color on that wheel and then grab the color directly across from it. That color is known as its complementary or contrasting color. Now pick a color next to it. That color is known as an analogous color. These colors blend really well together and hide things while still adding color to the scene.
Applying to maps
So through the topic of eye catching you already know when to use high contrast colors. Place purple weapons on a yellow backdrop in order to draw attention to them as incentives. Place a dark red door in a bright green wall to show players that it exists. Place yellow explosives against a dark gray wall in order to make them aware of the deterrent. So when do you want to hide something? Why not just high contrast everything in the scene to draw attention to it? Because the more things that are trying to pull attention the less affect each one has on the player. So next to that purple weapon on the yellow backdrop don’t place purple chairs around it or people may miss the purple weapon and only see the purple chairs and move on. Scenery and other objects that help smooth out the feeling of the map, that aren’t necessarily important to gameplay, need to use low contrast in order to not draw too much attention to them. They are there to complete the whole experience and keep the map from feeling bland; not to draw attention.