There is no substitute for orange. The color orange sits on the color wheel between the primaries red and yellow. It’s a mixture of those two warm colors. No other primary or secondary color is situated between two warm colors. In one direction orange leans to red and in the opposite direction it leans to yellow. That’s why orange is the warmest color.
I’ve often wondered why orange and black are Halloween colors. Maybe orange serves to oppose (or compliment?) the dark cold black on Halloween. Black is often associated with dark spirits, death and the cold night, while orange is associated with life, the harvest and fire.
On a recent trip to the US (in the town of Orange, Connecticut!), I was able to enjoy the height of fall foliage in New England, and to be reminded how truly Orange it is.