I brewed one last year and did one this year again, both with fresh raspberries. I used 1 Qt last year and 2 Qt this year. Even though it seems low, 1 qt is the sweet spot for balance IMO. This years rasp wheat made with 2 qt was a little too fruity and over shadowed everything else.
With 1 qt, the color was a very nice pink but turned a little brown after several months. I think the key is to try to avoid oxidation as much as possible so use a carboy with little headspace and fill bottles pretty high.
If you need advice on using fresh raspberries, I would be happy to post what I do to clean them. I highly recommend using real fruit instead of extracts because you get a lot more flavor and aroma than extracts.