Color suggestion needed for this Color

I am Fresher in Graphic Designer, Here i am developing UI for iPhone App in which in Navigation bar i used this Color but My requriment like use font color which are focus on eye i tried blue colors all but in iphone it's transperent theme so color are not focusing on eye .

can anyone help me to found textColor on this Background ... my back ground Color is Red :90 Green :90 Blue :90

which text color i used in transperent theme so it's focusing on eye , Here's my background