Swim shorts are not only attractive, they are also very versatile. They can be used for swimming, of course, but they can also be worn as shorts. Either way, they cover more of your thighs than traditional swimwear would. Black seems to be a very popular color for this type of garment, but along with plain designs, there are also plenty available with some adornment such as stripes and other patterns.
Here’s an example – I like the black and teal combination:
Womens plus size long swim shorts pictured: Women’s Plus Size Chlorine Proof Shorts for Swim or Gym by HydroChic