虹 is a Chinese hanzi, listed here under the keyword “rainbow”. It is built from 虫 (insects) and 工 (labor). It appears as a component in 1 other character in this index.
On KumiJi Glyph Explorer, open the parts search and type “insects” + “labor”. 虹 is among the results, together with every other character containing the same shapes.
Open 虹 in the interactive kanji search
to expand every part down to its smallest pieces, add your own names and mnemonic stories,
or search for other characters by their parts.