Here is a color palette that represents a rude, cold-hearted character, featuring shades of black, white, blue, and gray:

 <Cold Hearted Character>
1. Midnight Black - 
                            
                            #000000
                         - A deep, intense black that embodies darkness and mystery.
2. Icy White - 
                            
                            #F0F0F0
                         - A stark, crisp white that represents coldness and detachment.
3. Frostbite Blue - 
                            
                            #1E90FF
                         - A bright, icy blue that conveys a sense of chill and aloofness.
4. Steel Gray - 
                            
                            #A9A9A9
                         - A muted gray that reflects a hardened, emotionless attitude.

This color palette combines dark and cool tones to evoke feelings of coldness and isolation, mirroring the characteristics of a rude, cold-hearted character.

Would you like to explore different shades or perhaps the application of this palette in a specific design context?