Is it small brown spots or large areas of discolored skin?
Are you able to take a photo for us to look at?
Do the spots fade, or are you getting more?
If you can see the tree icon on the JA toolbar, then use it to add the images, or email firstname.lastname@example.org who can post them for you.
It would also be helpful to know if you have any medical problems and what type of skin you have (fair, olive etc)
Thank you for the images, looking at them I would say that this was possibly melanin deposition in the skin due to aging. The other possibility is hemosiderin deposition due to venous stasis.
The good news is that it is not sinister, and is a cosmetic problem only. However there is no way to remove the effect.
You would need to see a dermatologist to confirm this in person. If the problem is hemosiderin deposits then reducing weight, wearing support hosiery and increasing exercise may reduce the spread. I would also suggest that you use a total sunblock in the sun. Good moisturizing is also a good idea to help look after the skin.