I mostly agree with Squirrel. I think you'd look good with shorter sides, and keeping the scruffiness on top. As for colour, experiment and go with a colour that appeals to your personality. Maybe on the brown side of blonde rather than being so close to platinum. From the photos it looks like you have cool tone skin, so probably better to stick to cool shades like ash rather than golden blonde. You can look up colour charts online to get ideas.
But I do like your hair as it is now, it seems to suit you.