Maybe I'm deluding myself, but doesn't ANY outfit have the potential to look dated?
Suz, you don't have a frumpy bone in your body so your version of cropped white pants, fuchsia top, and pewter sandals isn't anything like the "uniform" that rabbit is referencing. Which brings me back to my point--switching from crops to a dress and sandals isn't going to rescue anyone from frumpiness; a dress and sandals, or a midi skirt and T, can be every bit as frumpy as cropped pants and a print top. As Angie keeps trying to drill home, it's the DETAILS that switch an outfit from frumpy to current, and the rest of the package--hair, eyewear, watch--that turn the age switch on or off.
It's that sense of knowing your own style, being comfortable in your skin, and giving a nod to what is currently going on in fashion in your outfits that distinguishes a fashionable older woman from a frumpy one.
ETA: Rachylou, I think it's that giddiness and aura of potential that imbues even the strangest of outfits with such charm when worn by a young woman. Maybe, as older woman, we ought to love that about them instead of trying to emulate or re-capture it?