According to Allure, there are nail polish colors that can significantly de-age your hands. While sheer and subtle colors are more natural looking, they "bring all the attention to your hands," according to Ji Baek of Rescue Beauty Lounge. If you want to draw the attention away from your hands and have people just look at your nails, go with a red color. 

Red is such a classic nail color that it's not even a hard switch to make. You should go for more orange-red than blue-red colors, though (via 40+ Style). The blue tone will bring out the veins in your hands, which you don't want. As a matter of fact, you should try to avoid dark colors in general. Any dark tones will emphasize dark spots on your hands from aging and sun damage. However, if you really aren't a nail color person and prefer something neutral, you can always go with white. According to Showbiz CheatSheet, even though it's not a vibrant hue, it is bright. So, it will draw the attention back to the nails and away from your hands, which is what you're really trying to go for.