Why are the colors on my photoshop jpeg pic so bright?

I have been designing website mock ups in Photoshop. The colors I select look as they should when I view the psd and jpeg in photoshop. The main color I use is a very dark Navy Blue, when I view the picture in the program and in in windows explorer it looks like it should. On a browser and on my phone I get this very bright blue color. Does anyone know why the file is doing that? My phone (iPhone) and my browser (firefox) makes the colors way brighter than they are supposed to be. If you know what is going on please explain it too me and how I can fix it. Thank you.

Added (1). Update* When I take a look at the jpeg in internet explorer it is displaying the correct colors. It only brightens the colors on ios device, chrome, and mozilla. I checked a family members android device and the colors were correct on there as well.

Because the colours allowed on a web site need to be selected by their colour number, and Potoshop is probably creating them form a palette. Web sites do NOT recognise palettes. Photshopis totally incapable of generating a good web layout unless you know enough html, php and javscrit to modify them from the page. Photoshop is only good for creating backgrounds and images.

Does your document have a color profile other than sRGB? Check your color settings to see if the "working profile" was changed or set from the start. Many browsers still do not apply the embedded color profile and default back to sRGB.

Different screens (such as the iPhone) can also make colors appear different from what you designed. This can't be helped.