Colors of many roses will change with the weather. You'll probably get the pink edges in the fall, along with much bigger flowers, at least when the plant matures. It is hardy for a white HT, so a good choice for you.

This comment is from rosetom in response to a query on white roses in the Roses forum:

'Garden Party may have a creamy tint before the flower is fully open, or in cool weather, and the petal edges will blush pink on the outer tips. In full sun and warm weather, the flower is consistently white when mature, with just the slightest tinge of pink shading - sometimes, none at all.'

I have Garden Party as well, and all blooms so far have shown the pink tint-but I have it in partial shade in the morning-so perhaps this makes the difference.

bren

Well, you were correct. I am now getting some pink edged roses now that it is a bit cooler. YAAAY!
Thank you for your info.
Sandy

This is my favorite rose, It is now 4 yrs in my garden and the pink edges and fragrance is always in the cooler spring. Now if I could just keep the beetles off her:(