How can I change the font color in FTGL?
Simply use a glColor
call before asking the font to render; you may need to disable lighting depending on your situation. Here's an example for C++:
FTFont *myfont= new FTBufferFont("myfontfile.ttf");
glPushAttrib(GL_ALL_ATTRIB_BITS);
glDisable(GL_LIGHTING);
glDisable(GL_DEPTH_TEST);
glColor4d(1.0, 0.0, 0.0, 1.0);
myfont->Render("Hello world");
glPopAttrib();