I added a configuration file (config.yml) in which you can choose your colors based on the RGB system, for each major damagetype.
By default, its configured as follows:

• MAGIC (magic) (95, 10, 95)
• MELEE (attack, sweep, thorns) (100, 100, 100)
• POISON (poison) (0, 100, 20)
• FIRE (fire, fire tick, lava, hot floor) (200, 90, 25)
• RANGED (projectile) (130, 70, 0)
• OTHER (everything else) (130, 130, 30)
  

You can change the color by updating the numbers between the bracket up to (255, 255, 255)