On Saturday, I was shown a beautiful lemon yellow crab spider dangling from our garden gate. It looked very conspicuous and vulnerable so I relocated it onto a lemon yellow erysimum thinking that it would enjoy the colour match. This perennial wallflower has amazing blooms which start lemon yellow and turn purple with age. But the crab spider determined to cling to a purple flower and was still there yesterday. Crab spiders can change colour from white to yellow, but sadly not to purple.