I do know that siamese kitties respond to sunlight. When I lived in the north north that seemed dark and short days, the kitties were dark brown. Then once I got to this wonderful long days of sunlight location the same kitties are light tan. They vary slightly between summer and winter, but the general latitude makes a huge difference. I'd never really paid that much attention to other breeds. I only have one Siamese left now, she is really old - almost 19 years! But she's a happy ole' critter. (and tan now)