Posted: 28/07/2014 at 11:02
It's looking sorry for itself simply because the grass has been allowed to grow too long - the base of the stems have been starved of light. Now that it's been cut it will start to green up - regular mowing (once a week - not too short) will soon have it looking better.
At this time of year I find an application of seaweed fertiliser sprinkled on before a good heavy downpour helps the grass to green up as well. If it doesn't rain then you'll need to water it in - give it a good soaking.
Then in the Autumn you spike it all over with a fork to aerate it and aid drainage for the winter, and then give it a proprietary autumn feed and it should be fine.