I am currently studying kanji by using a number of sites, some of which provide mnemonics to aid in learning. While not a specific radical per se (I think), the top portions of the following characters, 恋, 変, and 湾 are often thought of as a simplification of the character for red: 赤. Thus there are mnemonics provided for kanji like those mentioned that use this idea of "red."
However, http://www.kanjinetworks.com states that the etymology of this (quasi-)radical is as follows:
䜌 (Type 1 Phonetic) is 絲 (糸 thread doubled, a character now subsumed in 糸) + 言 words (in its original sense of making verbal distinctions → distinguish) → make tangled threads distinct by stretching and untangling them.
In other words, rather than "red," it is in fact a simplification of an archaic character related to the "thread" radical, 糸.
I am interested to know if this is correct, and how native Japanese perceive or conceptualize this (quasi-)radical--as being related to 糸, 赤 or something altogether different.
For example, here is the whole entry from the site on the kanji 変 :
変 (9) ヘン か（える・わる） Formerly 變
As per 䜌 (Type 5 Phonetic) as described in 恋 (tangled) + 攵 action indicator → an attempt to untangle a volatile situation, that leads to change → unusual; unusual/wondrous event; political event; internal disturbance.