I don't know that the re in "red" and れ really sound nothing alike, though. If you want to reduce it down to something simplistic, "ray" would be a lot closer,

I don't know that the re in "red" and れ really sound nothing alike, though. If you want to reduce it down to something simplistic, "ray" would be a lot closer, if still not actually all that close. For the r sound specifically, it's like 60% r, 30% l, 10% d. Most people don't struggle with getting it passable once someone teaches them that it's more about tongue positioning than anything. Have someone say "la" and "da" back and forth a few times, tell them to position their tongue touching the roof of their mouth in between the position it is for la and da while trying to make an r sound, and they'll probably be pretty close. And once your understand where the difference is on pronunciation vs an english r, you know what to start tweaking as you try to match native pronunciation.