It doesn't take a lot of yarn to make a hat, and granny squares can be made from small scraps of yarn in many colors. Even solid granny squares use very little yarn. So what if they're all different? Someone somewhere will be glad to have a crazy-quilt of a blanket or afghan that will warm their heart as well as their lap. Many organizations offer to collect squares to join to make an afghan, so it doesn't matter if no two are alike.
Get together with your church or other group to clean out your collective yarn hoards or make it a home school project with the kids. Don't know what or where you can donate? Look here for ideas.
P.S. Don't forget to send me your free knit and crochet patterns. Click the links in the bar at the top of the page.