Change colour of a textured surface

I'm trying to manually colour a surface that already has a texture on it. Basically in Unwrap I can texture the faces and change the Diffuse colour to give it a red hue (or whatever colour). However, I want to be able to change the colour in B3D without painting it with a brush as that paints over the texture. I tried changing the colour of the vertices like this but it doesn't do anything:

For Local i:Int=1 To CountVertices(surfSeat)-1
	VertexColor(surfSeat, i, 255,0,0)
Next

Can it be done?

Surely, if you don't want the brush to replace your texture you use BrushTexture() so that the texture is the one you already had on there?

VertexColor works, but you'll need to enable vertex colors. EntityFX(Ent,2) does that. It's been years since I used B3D, so I can't be 100% sure if you need any other EntityFX flags to use it. I don't think so, but if it doesn't work you can try the other flags as well as flag 2.

You tried entitycolor?