Never tried the Rainbow thingys! Have upgraded the bulbs to Osram silver stars and find they do give a whiter light (They're Xenon rather than Halogen). If I remember right, they are 60/55W. They've been in for about 18 months with no problems. I wouldn't recommend going too high on the wattage though; the SVS has plastic lenses so may be affected by the extra heat.
Hope this helps
Rich
