Color profile

Why does my image look like this on my computer...?

...but look washed-out like this on my website?

Use sRGB

If the image was captured on a slide scanner or a special digital camera, you may need to adjust the color profile by changing it to sRGB before upload. 

The easiest way to convert an image to sRGB is to use the instructions for exporting images from PhotoShop or Apple Photos.