DntWrryBeHappy21's method will work....but this might save you some time. Depends, really....
--Take the polygonal lasso tool and
do not select the magnetic version. Now you have to keep in mind a simple principal: Small straight lines make very good curves.
--Roughly highlight your stripes using short line segments. (Lots of clicking)
--copy/paste this selection into a new layer
--refine, reshape, generally finish the stripes to your liking.
--select this layer, and go to the hue/saturation option box. Click the check-box labeled "colorize". And choose the color you'd like the stripes to be. OR...in your case, choose the layer, and go into the brightness/contrast box and darken the striped to your liking.
Hope that helped out a little bit.