In this world (otherwise the same as Earth), people would have an appearance based on their characters. If someone does something bad, his skin gets a red stain and if he does something good then his new stain is blue. The size of these stains are based on that how important the deed was. The richness of stains stands for how hard is to decide if it was bad or wrong. (The decision is made by some nature powers or god, the people don't know)
Probably nobody would be just blue or red, all people would by colourful.
How would this change the way people look at each other and what they think about each other? For example, would this have some impact on the judiciary?