Simon wrote:
I am pretty sure I remember scaffold tubes come with a colour code
for Aluminium and steel poles, can anyone tell me what they are and
describe them for me?

Other than colouring poles for company identification you will find that a colour code is used for the identifcation of the material from which the pole is made. Certain grades of aluminium are coded yellow/blue. This applies to all metals. In much the same way various gas bottles are coded, grey for nitrogen, black for carbon dioxide etc there is a chart which lays down the coding system. Try as I might I cant find it through google.