Dear Gandalf and Sparrow,
It is very easy,
You must be colour safe. How ist it possible to become colour safe??
1. Pass the ishihara plates
2. pass an alternate colour vision test
First you begin with the plates. If you are not be able to read those charts correctly you need to do an alternate test.
alternate test valid for JAA also FAA
1. anomaloscope test: ( 1 circel is half red/green. with a turning knob. you need to match the circel into 1 complete colour by turning the knob.) if your matching range falls within the limit you pass.
2. lantern test (1): at a distance of +- 4/5 meter you need to indentify little illuminated leds. you are sitting in a dark room.
the leds can be red/green/white.
In all different ways (red--green)(red--red)(green--white).
you pass if you indentify all lights correct.
3. lantern test (2): at a distance of +-4 meters you need to indentify illuminated flashing lights.
You are whatching to a computer monitor. In the center of the screen you will see a flashing light for 1/10 second. it can be red, green, blue, yellow, or orange.
the light signal has got size of 0,5 cm so it is a verry small size.
indentify them all correct and you pass.
These are the only tests that are valid for a JAA medical.
good luck