This is about dying but not about death. It is about the word “dying”:
- Dying = death (death is highly irregular, and it cuts life short)
- Dyeing = coloring (coloring with dye is not irregular)
- Dieing = cutting a shape with a die (cutting shapes is not irregular)
That’s how you can remember which of dying/dyeing/dieing you want. The irregular verb death is the irregular activity which cuts life (and the word) short.