Colour Scheme for my game!!!

For my ww2 Game i am going to keep to 4 colours which are blue (this will be used for the sky),
Grey (This will be used for the background of the game at night), Dark Green (This is used for text and the background hills and finally black (this will be used for the some titles and the outlines of the object's in my game. I may add a few more colours but the one's i mentioned will be the main colours for the game.

The reason i picked one light colour was for the sky but the rest are dark because the world war was a very dark time and these were the colours you saw in the world war.