Please help! What do I wear to a graveside service???

I don't even know this woman who passed away. I guess she was older and the didn't find her for several days so the service was put together very quickly. In the Bishop's haste to get things coordinated, he asked me to sing some songs at the graveside service tomorrow. But what do I wear? It's outside (obviously) and it's REALLY hot here (97 today). Should I REALLY wear black or would a long kahki skirt be ok? I don't even know what is appropriate to wear to a funeral, the only ones I have been to have been my great grandparents...help please!

[AngelaS]

Wear something conservative and shoes you can walk across grass in. :D