Usually. It depends what is meant by "3 colors". If the cat just has a lot of different shades of color, that may not be an actual tortie. And torties don't need to have 3 colors; they can just be black and red.
The color gene for cats is on the X chromosome (white is different, not a true color). Males only have one X chromosome (unless he has a chromosomal defect like XXY or some other anomaly), and females have two. So females can have 2 different colors but males can only have 1.
So if a cat has black, true red, and white, that cat is almost certainly a female (about 1 in 3000 chance it's male). But some brown tabbies have a very warm shade of brown that looks red, so it can be a little hard to tell the difference sometimes.
Are you asking about a specific cat? If so, post a pic and we'll see what we can figure out!
Cats with red and black coloring (or the dilute version, cream and blue), with or without white patches, are almost always female. In order for a cat to have both red and black (tortie, dilute tortie, tortie and white, or calico cats), they need have both the O (coding for orange) and o (coding for not orange) alleles. O and o sit on the X-chromosome. Therefore, for a cat to be Oo, they need to have two X-chromosomes. In order for a male cat to be a calico or a tortie, they would need to inherit XXY, the equivalent of in Klinefelter’s syndrome in humans. Only 1/3000 calico and tortie cats are male, and they are typically sterile.