There are better options than gels, now. The flip type filters allow you to use a filter...or not. If you go shallow, you will not want a filter. Deeper? Yes. Backscatter offers a decent one.
I have the flip red filter with the Macromate mini macro lens. I love the flip red filter.....not so happy with the macro lens.
I tried to post an image off the web of it, but the forum won't allow it? What the heck?
A cropped image of my rig.