The second session of the CSS Battles at JSCraftCamp 2024 started with this puzzle. There were multiple ideas what this could be: Four divs for each color. One background with linear gradient and a black div on top. One div with different border colors. The last one seemed to be the simplest of them and we used this to quickly create it. We looked a bit into code golfing but we could see that the best solution seemed to use some other idea.

We didn't bother googling it, but since I got asked, I shared how I found out about better solutions usually: Check the leaderboard, google for the names of the first places, check their GitHub or websites whether they share their solutions somewhere.