The TMC4C123G Tiva Launchpad is shipped with a pre-loaded RGB demo application. The source code for this application can be found in your Tivaware software download.
After downloading and extracting TivaWare files the source code for launchpad start up application at :
{your tivaware folder}\examples\boards\ek-tm4c123gxl\qs-rgb
After downloading and extracting TivaWare files the source code for launchpad start up application at :
{your tivaware folder}\examples\boards\ek-tm4c123gxl\qs-rgb