Is this a positive OPK?

Breanne
This is my first cycle using OPKs, so I'm a newbie to this! The one on the bottom was from this morning. Is that a positive, or should it be darker? Or will I just not know until I've taken one that becomes darker or lighter? 
ETA June 27: Added pic of OPK from this morning, and it looks lighter than yesterday's. 😕