As with the original layout still widely available today, the coloured blocks are alternating red and black for numbers 1 through 36.
In contrast, in france they wheel generates a house edge of just 2.7%, facilitating a reduction of 1.4% on all bets to do with even-money. https://gamemodios.com/tip/danh-gia-nha-cai-uy-tin-rikvip