If you are using first time or have least knowledge about pure leather then don't worry about its colour variation. Pure leather wallets get more beautiful on ageing. These are not PU which will contain shine on its surface. If leather gets too wet, dry it slowly. Speed drying leather changes its chemical structure and you end up with stiff crinkle cut chaos. So aim for room temperature drying with gentle air rather than direct heater time with a hair-dryer.