First, in the playback menu, find the display options and enable the EXIF data (and anything else you want to see, like the histogram). The EXIF data should include white balance setting.

Then after a shot, use the up/down arrows to cycle through the various displays.

If you want to see the white balance setting, then in the playback menu, find the playback display options and enable "shooting data" which will include aperture, shutter speed, white balance and other settings.

The playback display options also include an option to show the RGB histogram, if that's what you mean.

Once enabled, you can cycle through the displays using up/down arrows.