FYI, Christmas Tree Coral is almost impossible to keep.
I've read that the color of the tubing doesn't mean anything because they flow keeps them clear. I prefer clear though so I can see what's going on in the tube.
Clear can allow algae growth in the tube, slowing your flow. If you want pods in your sump, toss a bunch of live rubble and a small ball of cheato in there. put some of your rubble in a plastic mesh bag so that you can transfer it to the main tank. this way you can get live pods in your tank without them going through your return pump.
Darn, I had cheato. But Cheato is algae, algae is a photosynthetic active organism group, as in need light. No light down there ( yet ). With and with out light what exactly will grow down there?
pods will grow without light. btw, you can use one of the regular minifluorescents for your fuge (ya know, the curly energysavers) just make sure its a daylight spectrum, (6700k) and not the cool white or warm white bulbs.
the benefits of using one of the energysaver bulbs is that they are CHEAP. both in initial cost and in running them. so are the fixtures for em. Much cheaper than getting a mini PC or other comparable fuge light. That way you can have chaeto, which is excellent for pod growth and for reducing nitrates.
any light fixture that is rated for outdoor use and can take regular bulbs will work. Then get a daylight bulb (preferably a spotlight style) and you're good to go. If you are short of room in your sump, you can always use a small plastic soap dish or make a cage out of egg-crate to hold a small ball of chaeto. hope this all makes sense.
go to your local hardware store and check their outdoor light fixtures. Generally flood light type fixtures are what you're looking for. just make sure it has an adequate gasket to seal the bulb so salt creep doesn't find its way in. This will probably be the cheapest way to do it. someone (possibly woodstock) has a couple of threads about this exact setup. do a search and see what you can find on RS.