If you work with photos in a wide-gamut color working space such as ProPhoto RGB or Adobe RGB, image colors may change when viewed in a web gallery by a browser that doesn’t read embedded color profiles. If this happens, try converting the image profiles to sRGB (which most browsers use as a default) before optimizing them or including them in a Web Photo Gallery. Convert them to sRGB in one of the following ways. It is a good idea to work with a copy of the images.
To convert a single image, choose Edit > Convert To Profile and then choose sRGB. See Assign or remove a color profile (Illustrator, Photoshop).
To convert a folder of images, use the Image Processor. Choose File > Scripts > Image Processor. See Convert files with the Image Processor.
If you use the Image Processor, you can save the files directly to JPEG format in the size that you want them. If you do so, make sure to turn Resize Images off in the Large Image options.