Unicode doesn’t have a RAINBOW FLAG code point, but you can use
U+1F3F3 WAVING WHITE FLAG
U+200D ZERO WIDTH JOINER
U+1F308 RAINBOW

See http://unicode.org/reports/tr51/#Multi_Person_Groupings … and http://unicode.org/reports/tr51/#ZWJ_Sequences … for more examples of combined emoji using ZWJ.
12:19 AM - 28 Jun 2015
0 replies
4 retweets
8 likes
Loading seems to be taking a while.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.
JavaScript, HTML, CSS, HTTP, performance, security, Bash, Unicode, i18n, macOS.