Hey there,
i guess this is a popular option in
online poker. It makes it easier to identify flushes and read cards quickly, especially when playing multiple tables at once. Live games typically use standard two-color decks. A four-color deck can be beneficial for players with vision impairments. I sometimes wonder, why they're not a standart, even in live games. There are still plenty of mistakes inattentive people can make, so why not changing that overall.