I think I ordered mine (for wedding favors also) about 2 months before. That way it gave them time to get better if they came a little rough-looking and if I needed to replenish them with store-bought ones (which I did do for about half of them).
Do you have them in bright, indirect light? That was the one thing that really made the difference for me. Also, it helps if you make sure that your succulents either are in a container with rocks at the bottom or with a drainage hole so that the roots stay dry most of the time. I would pluck one of the fingers off the plants you are trying to save and start over with new soil and a new container! Hope this helps--good luck!
mountaincrestgardens (dot com forward slash) hardy-succulents/ has a whole list of succulents hardy to zone 5. I wrote the link strange because I wasn't sure if Amazon blocks links.
Thank you for your interest in our shop! For any event, we recommend ordering about a week or 2 before the event to allow the little guys to recover from their trip. As for the colors, we sadly cannot guarantee colors due to our inventory changing daily and the seasons change.