https://www.amazon.com/Ideal-0X8-28280-Rage-Card-Game/dp/B00E4H14RI

It's six colors with numbers 0-16 on them. I design a lot of card games or games involving cards, and this has been invaluable to pretty much immediately playtest my ideas, as a standard set of playing cards only has 4 suits, and I usually need more than that (plus I prefer a large number on the card instead of a bunch of symbols or JQKA on them).

You can use a rage deck to play a lot of modern card games, to give you an idea of how useful it can be: https://boardgamegeek.com/geeklist/1907/games-playable-rage-deck-not-ccg-please-add

You can also use a Sticheln game, it's basically the same thing, in fact I prefer the look of their cards, but Rage decks are a bit cheaper as they don't have to be imported from Germany: https://www.amazon.com/Sticheln-Import-allemand-by-NSV/dp/B00A6N4JJE

I also use the 6 Nimmt! deck sometimes, as it's just numbers from 1 to 103, which is useful for a couple of my designs: https://www.amazon.com/Mayfair-Games-ASI5714-6-Nimmt/dp/B013FAC20C/

6 Nimmt! deck can also be used to play several different games: https://boardgamegeek.com/geeklist/24313/games-playable-deck-6-nimmtor-category-5-please-ad