Each Bar is worth 1 HP. The Color show how much you have. Red Bars show you got hit. Blue Bar is the Standard and range from 1-49 HP. Once you got more as 50 HP the Color will change to Lightblue and range from 50-59 HP. This will continue until 100 HP where the Bars will be white and is the Maximum. This is also true for the Enemy Bars (especially the Bosses.)