die, dye

Die or die means to cease living; to expire or pass on--
Life insurance pays a sum of money to the beneficiary when you die.
I hope this plant doesn't die. It doesn't look healthy.
Die also means the mold used to cast metal machine parts, or other parts--
He works in the tool and die department.
When the die wears out, the parts won't work properly.
Die is also the singular ( one, and only one ) of dice--
The die is cast.
Roll the die.

Dye or dye ( rhymes with die ) means to use chemicals to alter or change the color of something, generally hair or clothing--
Is she a natural blonde, or does she dye her hair?
Indigo is used to dye blue jeans.
Dye also means the stuff used to alter or change the color of something--
He bought  package of dye.
This dye came out a funny color.

Now that you know that, you can say--
"Some people dye their hair dark until they die."

Note--the past tense ( yesterday, or some time ago ) of "die" is died--
He was only sixty when he died.
The past tense of "dye" is dyed--
She dyed her hair red, but then changed her mind and dyed it blonde.
Note # 2--the plural ( more than one ) form of "die" is dies--
The dies are worn. The parts will be substandard.
"Dies"( dize ) is also the third person singular ( he, she, it ) form of "die"--
She said she'll treasure that memory until she dies.
"Dice" may also be the plural ( more than one ) of die--
Roll the dice. It's your turn.
Note # 3--the plural of "dye" is dyes--
She tried several different dyes before she found one she liked.
"Dyes" ( dize ) is also the third person singular ( he, she, it ) form of "dye"--
She dyes her hair. Real red hair doesn't look like that.