Peas going pale

My Hurst and Kelverdon wonder peas have been very lush and healthy and producing abundant crops. Now the top part of the plants and some of the pods are going a very pale colour. I know some of the leaves have been eaten by snails and am wondering if this has caused it or are they just getting naturally to the end of their life ?

Cut all mine down today But the next sowing are ready ro go out
How long do you keep the roots in Peapod? Til they've rotted down?  I never know & usually leave til the autumns digging!!

I need the space when they have finished to plant winter cabbage and the like so I will did it in the soil before I plant. Still more flowers on them at the moment though ;-)