I seeded some new perennial rye grass lawn areas (previously overgrown
flowerbeds) about a year ago and they've done quite well. But they turn
quite yellow in cool, wet weather like we're having now (I'm in Durham).
The old lawn areas seem to love this environment and go lush green,
while the new lawn slows its growth and yellows. I noticed this pattern
during some similar spells earlier in the year.

Any thoughts or suggestions?

BTW, it may be a red herring, but it's green and growing better around
the edges where it's up against paving. My soil is generally mildly
alkaline.