Inspired by the "240p test suite" (http://junkerhq.net/xrgb/index.php/240p_test_suite), I have made a little tool with 11 test patterns for testing the video output of Neo Geo systems.
The tool is intended for adjusting the picture of CRT monitors and for CMVS builders who want to test their modded arcade boards.

Particularly interesting is the "Color Bars" pattern which contains any RGB level of the base colors red, green, blue and white.

The tool is available for Neo Geo CD, MVS and AES and can be downloaded from my website:
http://www.neohomebrew.com/neo-geo-monitor-test.php

Here is a short video of the tool: