!$color

The !$color command sends a tellraw message colored as the input color.
i.e.
!red outputs USERNAME is RED
!electric_lime This text is electric lime outputs This text is electric lime
!#FFAA00 outputs USERNAME is MINECRAFT_GOLD
!#000080 Bottom Text outputs Bottom Text

List of colors

https://docs.google.com/spreadsheets/d/1QlfjmtmpB-MYX1ZbsiGLCDkXVtAKmiwaQGR1t7EFrbI/edit?usp=sharing