What is the missing one?
$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, $
[Some colours look alike, sorry about that, but then again you don't really need to be able to make a visual difference between them, do you? Oh and sorry for being slightly inconsistent just there - not a native speaker.]
Hint:
Should same colour digits be read from top to bottom or from left to right?
Here is a google sheet required by OmegaKrypton to make any analysis easier.