I can play only 1 map in the blue and grey mod, version 2.
I only see "honor redeemed" (in the color red) as a map from the blue and grey mappack. I have played and beat the level many times. When I click on the next level button it takes me to a normal myth 2 map.
I am running windows 98, myth 2 version 1.5, blue and grey version 2. It was a fresh install of blue and grey, I have since reinstalled and the same thing happens.
The simple reason is: there is just one solo map for blue and grey v2! :O Once you beat "honor redeemed", there is nothing more left except for the multiplayer maps...
Hint: When you hold down [Shift] while clicking on the New Game button, all available maps will appear.