I currently have a reservation for a hotel from 8/3-8/6 but would like to add 8/2. It looks like there is a waitlist option for 8/1 but it is blank/grayed out for 8/2. 
Does that mean that I have no chance of getting a room on that date?

Thanks for any help/ insight!

The grey means unavailable, so at least for now, there's nothing you can do, at least at that hotel.

It depends on what's most important to you. So, if you have a downtown hotel, it might be worth it to you to look outside the housing block on normal channels for just the Wednesday night, sleep there for one night, and then go to you original hotel. If you don't care as much where you are, or if you are already needing to drive in, you can check for what's available with your new parameters and see if you like what's there. You can still modify your reservation (including the hotel where you will be staying) for free until July 17, and the modification doesn't happen until you agree to it, so you can click on "edit" for your current reservation to see what else is available.

Good luck!

Thank you! I appreciate the advice!

Just now, I checked on booking.com, and there is a room at the Tru by Hilton in downtown Indy for $211 (two queen beds) for Wednesday night. Most are more for downtown, but if you want to grab that (free cancellation), you might consider it!

That is awesome! I just booked, thank you so much!