http://www.fileden.com/files/2006/6/17/74021/wtfudge.jpg

Left: "Save for Web" preview Right: Original

Why is photoshop draining my pictures of color? I just started noticing this...

Image is set in RGB, and chaning the jpeg output quality makes no difference.

Photoshop is not draining your colors, it's converting them. This is a colorspace problem. Most DSLR's on the market today offer a choice somewhere in their menu system of taking pictures in one of two color modes: Adobe RGB 1998 (often abreviated as Adobe RGB, or just Adobe) and sRGB IE61966-2.1 (Usually shows up as sRGB). The two colorspaces are quite different. Adobe RGB has many more colors available, and therefor gives a truer representation of actual color. It's the default colorspace setting on most cameras. After all, why would you willingly limit your available colors?

Because sRGB is the proprietary colorspace for web use. When you use "Save for Web", the function automatically assumes you want to use the sRGB colorspace, and will convert the file to that mode if necessary.

Here's how to work with these changing modes: Start Photoshop, and go to Edit> Color Settings. You see the dialog box below:
http://i42.photobucket.com/albums/e313/zachtlr/ClrSetDB.jpg

If you're going to be working on an image that goes to the web, then set the top box, "RGB" (under the working spaces box) to sRGB IE61966-2.1 before you open the image. Doing this converts the image to what you see on the left before you make any adjustments. You open it in sRGB, edit it in sRGB, and save it in sRGB to get the best web image possible. If you're printing the image, use Adobe RGB to get the best color reproduction for your prints.

Now look at the dialog box again. About halfway down, you'll see a section titled "profile mismatches. The boxes marked "ask when opening", and "ask when pasting" are both checked on my system. So now, if I open an sRGB image with my colorspace set to Adobe RGB, I get a dialog box that tells me there's a conflict, and asks what I want to do about it. Sometimes, it's just an annoying message that I have to click to get rid of. But sometimes, it prevents me from making a serious judgement error.

Colorspaces can be confusing at first, so if you have any questions, feel free to ask.

- Joe U.

Thanks, Joe!

Thanks for taking the time to go in depth about it as well. You have helped me tremendously.