Did you find the Honda colour code on the subframe, under the seat?
To be frank I think you are going to struggle to find the RAL or Automotive paint codes of this scheme because I think originally the base colour will have been white paint and the blue and yellow highlights will have been applied in decal graphics....the tank was probably painted but all the rest was likely decals.
You could try to use a colour chip chart against some original panels/graphics and get the closest match. Or if you have access to an original panel/decal you could ask a paint supplier to scan it with the magic eye and give you the exact match (ironically I did this yesterday to get a like paint match for the Rothmans tank on my MC21).
Or you could paint it the colours you want, it's your bike, build it just how you like
Max