Thanks AKL for the 25lb and 50lb braid in white that you posted to me.
I have mostly been using the 30lb braid that I obtained from Ebay in black.
I have taken the double walled loop and turned it into a triple walled double loop for attaching nylon to fly line using loop to loop at each end as per the "getting my flies down thread". I believe that the black braid will be less visible than white when attaching a double walled loop to the T line and also found that the thinner braid was easier to use with the splicing needle.