It looks like a reversed 'S' passing through the centre square. Draw the first half starting from the left side clash going through the other 5 clashes and ending at the black square. Then continue on to the H in 'shaH' and end at the E in 32 across.
Despite reading various articles, web pages etc I am still no wiser about the colours and have been looking since Sunday lunchtime. The unclued answer is, according to everything I have read, made up of various colours but we can't be expected to include them all...or cane we?
If you Google the two-word 'observation' plus the unclued entry, some of the suggested answers should help you out. Alternatively have a look at the Wiki for the unclued entry. What you're looking for is there in the infobox. Just one colour for the unclued entry, the opposite colour for the curved line.
Thank you for that Rick DGD. I spent too much time Googling the unclued entry and the associated removed words. I now need to see if I cam apply Professor Maisie's helpful guidance successfully.