Pcbnew, Update pad colors in opengl mode

[Patrick Marmorat]

When I change colors in the render tab, only the grid color change instantly.
The other colors like anchors, through via, pads doesn't change, even when I press F3 (redraw).
For apply changes, I must go back to legacy canvas and return to opengl.

In default mode, all the colors change instantly.

Application: pcbnew
Version: 201609191018+7178~55~ubuntu16.04.1-, release build
Libraries: wxWidgets 3.0.2
           libcurl/7.47.0 OpenSSL/1.0.2g zlib/1.2.8 libidn/1.32 librtmp/2.3
Platform: Linux 4.4.0-38-generic i686, 32 bit, Little endian, wxGTK
- Build Info -
wxWidgets: 3.0.2 (wchar_t,wx containers,compatible with 2.8)
Boost: 1.58.0
Curl: 7.47.0
KiCad - Compiler: GCC 5.4.0 with C++ ABI 1009
        Settings: USE_WX_GRAPHICS_CONTEXT=OFF
                  USE_WX_OVERLAY=OFF
                  KICAD_SCRIPTING=ON
                  KICAD_SCRIPTING_MODULES=ON
                  KICAD_SCRIPTING_WXPYTHON=ON
                  BUILD_GITHUB_PLUGIN=ON
                  KICAD_USE_SCH_IO_MANAGER=OFF
                  KICAD_USE_OCE=ON