What is the "color filter" mentioned in the rules?

[3038922]

He’s used for vision sensors?
I can’t find the relevant documentation information. Can someone guide me?

[jpearman]

You can use color filters with the light sensor, an old thread where I did some analysis here.

LDRs, LEDs and the color of VEX field tiles

Part 1. One of the long term items on my “to do” list has been to get hold of a VEX light sensor and see how suitable it is for detecting colored objects, specifically the color of the alliance starting tile. Before jumping into that I’m going to deviate a little into some basic color science that needs, at least partially, to be understood so the behavior of the light sensor is a little clearer. As you all know from high school physics, visible light is part of the electromagnetic spectrum w…

[3038922]

Is it necessary for vision sensor to use this?

[Barin]

You are not allowed to use this with the Vision Sensor.

The Vision Sensor captures full color anyway, so a color filter would be pointless.