虹 is a Japanese kanji written with 9 strokes, listed here under the keyword “rainbow”. It is built from 工 (craft) and 虫 (insect). In Remembering the Kanji by James W. Heisig it is frame 559.
On KumiJi Glyph Explorer, open the parts search and type “craft” + “insect”. 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.