Orange cats are not always male, but the vast majority of them are. About 80% of orange cats are male due to the genetics of coat color being linked to the X chromosome. Male cats have one X and one Y chromosome (XY), so if they inherit the orange gene on their single X chromosome, they will be orange. Female cats have two X chromosomes (XX) and need to inherit the orange gene on both X chromosomes to have an orange coat, which is much less common. Therefore, female orange cats do exist but are rarer, making up about 20% of orange cats.
The orange fur color comes from a gene known as the "O gene" or a related mutation in the Arhgap36 gene, which is linked to the X chromosome. This genetic setup explains why orange coloring correlates heavily with male cats but does not exclude females from having this coat color.