You look around the classroom for something yellow and then in desperation say, “As yellow as this pencil.”
Hmmm. It’s not the best description is it? How about making an inspiration book to help? Find a notebook and write one adjective on each page, then have a look through magazines and cut out pictures for them. Try for 4 or 5 pictures for each one – but remember to ask for permission before cutting up other people’s magazines!
On my “yellow” page I have a daffodil, a canary, a newly-hatched chick, the sun, a buttercup and a banana. Now if someone asks me “how yellow?” I can tell them “buttercup yellow” or “as yellow as the sun.”
Your teacher won’t mind you using your inspirations book in the classroom as long as it is improving the quality of your writing.