(WHTM) — When you think of Halloween, you probably think of jack-o-lanterns, spooky movies, and trick-or-treaters. But there may be something else that comes to mind that many people relate to the holiday: the colors orange and black.

But why do we consider them the colors of Halloween?

According to Isle of Halloween, historically the Celts and the Druids celebrated a holiday called Samhain. Samhain is a Gaelic festival marking the end of the harvest season and the beginning of winter or the dark half of the year. It is celebrated during the evening of Oct. 31 and into Nov.1 each year.

It is also seen as a time to celebrate the lives of those who have died and often has people paying respects to all who have died before us.

The Isle of Halloween says that while taking part in Samhain, the color black is used. Symbolically, that color is used to represent death and darkness. Samhain has close ties with Halloween and the Isle of Halloween says Halloween is typically celebrated at night, so it is naturally associated with the color black.

Orange, on the other hand, is the complete opposite of black. It represents and celebrates the life and the bounty that comes with an autumn harvest. This color is a sharp contrast to black and can be seen as a warm and positive color. It is also the color of fire, pumpkins and some leaves turn orange during autumn, which also may be why it is associated with Halloween.

Other colors have also been considered ‘Halloween’ colors, such as purple and green. Isle of Halloween says Purple is associated with mystery and witches during the holiday. Throughout history, witches have been depicted as wearing all black, but during modern times you will see them depicted having hints of purple on their clothing or hats.

Green is another color sometimes associated with Halloween. This one is straightforward; it depicts monsters and slime and is also used in glow-in-the-dark objects used for Halloween decoration. And if you see a green mist, you probably want to steer clear of it, as it is unnatural and can be frightening which are the feelings sometimes associated with the holiday.