I have almost finished this. I only have the 4 snowflakes and curly-wurly bits down the sides to go. Unfortunately I still can't show you a picture so you're just going to have to take my word for it.
I had done most of the first snowflake by going up and down the arms and then I decided that looked silly so now I'm ripping it out and I'm going to try going round and round in circles from the centre out - see if that will help the colour variation. The thread goes from quite light to quite dark, so it's quite obvious the direction of stitching and where the changes are. I'm trying to get something that will look smooth and flow nicely and not have such large colour jumps between stitches. I'll see how the circle method goes.