35535

My solution is:
red = 4n-3
as for the sequence I saw,
1, 5, 9, 13, 17...
With this pattern I worked out the nth term which one bit was 4n as it kept simultaneously added 4 and then I listed the 4 times table which were,
4, 8, 12, 16, 20...
so from this I need to know what I have to do get 4 to 1 which was to subtract 3 for each n number. The nth term was eventually 4n-3.

You do the same for the other numbers which all have the same traffic colour and find what rule each colour.

Yellow = 4n-2
Green = 11n-7
Blue = 2n+1