This is a very classic sounding tele neck pickup. Alnico 3 magnets and a slighly "hotter" wind Give the RED option the traditional tele sound and make it more robust while maintaining very good clarity.
This is a very classic sounding tele bridge pickup. It has the "twang" that a Tele is known for. Alnico 3 magnets and an 8.2 K wind make the RED model very versatile. Turn your volume all the way up and it'll hit the amp nice and hard. Turn it down a touch and it will sweeten right up.
The BLUE option gives you an alnico 5 magnet for a bit more attack and a bit punchier sound.