Stay away from blue lights. They are very bad for your night vision, and for the night vision of others who share the road with you. The rod cells in your retinas are adapted to detect details and motion at low light levels, but are easily overwhelmed and rendered useless in bright light or blue light. They take up to 30 minutes to recover after exposure to light sources with a high color temperature. This is why you are "night-blind" after you turn off the bathroom light and try to stumble back to bed in the dark.
The cone cells in your retina are poor light receptors, but have adapted to detect colors. This is why things at night appear "grayer" than they do by day. Your eyes are sensing low light with rod cells, but the cone cells do not have enough light to operate.
Blue headlights, most LED lamps and the SilverStar Ultra (4100K) all overwhelm your eyes' rod cells and stimulate the cone cells. This gives you the illusion that you're seeing things more clearly, but in actual fact, you're blind to anything that isn't in the direct path of your headlights.
You're also blinding everyone else on the road with you, which is inconsiderate and unsafe. You're best off using standard headlamps in the 3200K color temperature range. All headlamps dim with age. After four years of use, they should be replaced whether they still illuminate or not.
I'm probably going to need to get some popcorn now...