Colormap idea

A nice website for your colormap:

http://colorbrewer2.org/#type=diverging&scheme=BrBG&n=3

There is also a matlab colormap function based on this:

https://www.mathworks.com/matlabcentral/fileexchange/42673-beautiful-and-distinguishable-line-colors-+-colormap

Another website for color design: https://color.adobe.com/create/color-wheel/ .  This one is more suitable for presentation and posters