[ros-users] <color> attribute in world files

When I attempt to set the color of an object, it doesn't seem to
change. Is this expected/known behavior? If not, can somebody direct
me at the correct syntax for setting the color of an object?

I have found that I can set the color to blue as shown in
http://www.ros.org/wiki/simulator_gazebo/Tutorials/SpawningObjectInSimulation
by using a <material> element inside a <gazebo> element. What colors
beside blue are available? Where would I find those?

--wpd