Totally different thought - but if you want to conceal the marks on your legs - and want to look sort of summery - why not a ballet length chiffon or silk floaty thingy skirt and a body-concious close fitting top. You don't say how far down the leg the marks go, but assuming they stop above the ankle, you could wear pretty sandals. The dress you are looking at is pretty, but a short dress forces you to wear opaque or dark colors and a closed shoe, and the overall look is wintery.