When switching on my ignition I have to insert the code every time. What do I need to achieve it that I don't need to do this

Swap the red and yellow wires if it's an aftermarket radio.

 

Edited 20 October, 20178 yr by TMB

It's the factory head unit

I had this very problem fitting a factory cd player in place of a factory cassette player. The answer was like they say, i had to swap the yellow and red wires around. Ones the permanent live the other an ignition live.  No idea why as both Skoda parts but that solved it for me.