Etymology of ''blue'' and ''red''

Most of the colors, it seems, were so named after common things which “best represented” them.

However, I’ve drawn a blank on “blue” and “red.” From what I gathered from one source, “blue” might be related to some early words for “yellow,” but, why, I didn’t see.

“Red” seems to go back to an Indo-European root, but there was no indication of what it might have represented.

Anyone???

I did a report on the IE root “reudh-” (well more like a story that used all of the words from this root. For a History of English class) and basically it means “ruddy,” like the color your face gets when you’re sick/hot/embarassed. A lot of the words that came from this root have to do with illness, like reubella.

Check out this link to see a list of all the words that came from that root and their meanings. One example is the word for “robin” which has a red breast.

Here is the link for “bhel-” which is the root of “blue.” Seems like a lot of the words have to do with bright white or bright flame, which can look blue.