This call:
SEGGER_RTT_printf(0, "%sHello %s%s%s!\n", RTT_CTRL_RESET, RTT_CTRL_BG_BRIGHT_RED, RTT_CTRL_TEXT_BRIGHT_WHITE, "World");
Produces this output on the J-Link RTT Viewer:
e[0mHello e[4;41me[1;37mWorld!
The control codes are being printed rather than being acted upon.
Any ideas?