What Causes Yellow Dry Vaginal Discharge?

I'm a 25 year-old female, I've noticed that my underwear usually always has a light yellowish substance that is dry. It seems to always be there except during my period. Is this normal? It doesn't itch and I don't have pain. It doesn't really smell like anything. I use baby wipes throughout the day and I shower daily sometimes twice a day, I clean myself well, I don't shave or wax (I don't know if this could be a reason). This bothers me because I'm not sure if its normal and I don't like having to hand wash my underwear to get the dry yellow substance out. I'd just like to stop this nuisance. Thank you.