why the text color of the frame's name in rviz is white?

edit

I did not find tf_display.cpp in my computer, but I found tf_display.h which does not include color's lines.

I will add figure to my question as update. Will I need to build it as own visualization from source? If yes, does it need to modify something in launch file?

I downloaded it for kinetic from kinetic-devel and put it on my /catkin_ws/src/

I changed this line from

frame->name_text_->setColor(Ogre::ColourValue::White);

to

frame->name_text_->setColor(Ogre::ColourValue::Black);

and used catkin_make,

then used source ~/catkin_ws/devel/setup.bash

It works fine,

thank you so much for your help.

Note: all this modification is in the workstation part, not is in the robot part.