The color pattern consist of a series of pale , subrectangular blotches running down the center of the back , interspaced with dark , yellow @-@ edged hourglass markings . The flanks have a series of fawn or brown rhomboidal shapes , with light vertical central bars . The belly is pale with irregular brown or black blotches . The head is white or cream with a fine , dark central line , black spots on the rear corners , and a dark blue @-@ black triangle behind and below each eye . The iris colour is cream , yellow @-@ white , orange or silvery .