All I can see is a kind of pattern with the first four colours if you use the colours of thr rainbow in their correct order.
RED, ORANGE, YELLOW, GREEN, BLUE INDIGO, VIOLET
Jump (two) colours from red to arrive at green, followed by blue. Then jump (three) colours to arrive at orange.... Then what ??
As for the colours that Red, Green, Blue and orange are written in, I haven't got a clue ??
If you look at the colouring of the "google" logo, it goes
Blue, red, orange, blue, green, red
Reversed this = RGBORB
Therefore after Red Green Blue Orange it should be RED next
As the only answer red, is written in green, that is what I would go for. Answer a)