Are there terminals that support true color?
KDE Konsole has true colour support, i.e. every character can have a different 24-bit colour.
Xterm and most other terminal emulators these days have a palette of 256 colours, whereby each of those colours can be chosen out of the full 24-bit range.
I know I'm very late for the party, but I found this : a gist titled "True Color (16 million colors) support in various terminal applications and terminals", which gives information about which terminals support true colour and related discussions in the corresponding communities.