Brighter Lighting

I''m working on a game engine with vertex based lighting. Right now, the light at it''s brightest point is the same as the textures color. Is there a way to make the light actually cause the wall to look brighter then the actual texture? Here are two screenshots of what I mean. The first is how my engine currently looks, the second I edited in photoshop to show what I''m trying to get. http://www.babylonius.com/invasion/scene1.jpg http://www.babylonius.com/invasion/scene2.jpg I would appreciate any help anyone could give, thanks.