Thanks! Actually, yes, you can tint your light...
However, since original LightMask is in a "destination out" blend mode, you'll have to make another mask (I call it originally TintMask ) and synchronize its position, angle, etc. with the LightMask. You put your TintMask on top of all objects in the target level.
I am using the sine behavior for the opacity and size on the LightMask in order to give some flicker to it. Naturally, you do not see it on the picture, but the effect is just great