colors changing in the viewbook !

Well, color is a complicated issue. Web browsers (and the flash player) all use a so called sRGB color profile. Except some browsers like Safari can handle different color profiles, it is best to prepare your images in sRGB. Viewbook is using Flash to show it's images, which currently does not handle color profiles, but with Flash Player 10 it will. So we will be on top of this as soon as this player is adopted by enough people.

Here's a short article I found on how to make your images ready for the web:

"In order to get the best color rendition for a photo for the web as well as the highest quality image with the smallest file size for fastest display, the goal is an image that is 72 dpi, 8 bits, sRGB, jpg.

Let me translate: 72 dpi means 72 dots per inch. That is a typical grid of dots on a computer monitor. 8 bits is the lowest amount of color information packed into each dot, and that is also all a monitor and a web browser can deliver. SRGB is an "ICC Profile", a way of compacting the range of colors in a picture into the capabilities of the monitor. For example, paper can display a wider gamut of colors than a computer monitor so if we are printing we use a different color profile. The ICC Profile that works best for computer monitors is called sRGB. There are other RGB color profiles, but you want the one with the lower case "s" if you are preparing an image for the web. Note that this is the lowest common denominator, and you never want this profile for an image you intend to print. Finally, the file type you want is a jpg. This is a compressed format that is best for photos or images with continuous tone such as shadows. Use gif for images that are mostly solid colors such as logos.

Here's how to do this if you are using Photoshop CS3 (the menus are similar for earlier versions):

Pull down the "Image" menu and select "RGB Color" and "8 Bits/Channel". Then chose the "Edit" Menu and select "Convert to profile". Then chose "Profile sRGB IEC61966-2.1, Engine Adobe (ACE), Intent Relative Colorimetric, Use Blackpoint Compensation, Use Dither."

Then chose the "Edit" menu and "Save for Web & Devices". Click on "Image Size" and choose the size you want in pixels and "Quality Bicubic". In the upper left click on the "4-Up" tab. You can then pick the one that looks best. For photos chose, I usually select "JPEG High". Uncheck the boxes by ICC Profile" and "Progressive". "Blur" should be 0 and "Matte" should be blank. Now I know I said we want the sRGB profile and I just told you to uncheck the color profile box. That's because attaching the color profile to the document makes the image larger, and since we've already converted it to the sRGB profile which is optimized for the web, and most web browsers can't read profiles, we don't need it.

Finally, click the "Save" button, make sure the next window is set for "Format Images Only" and "Default Settings", give your document an appropriate name, make sure it has either a ".jpg" or ".gif" suffix, and click "Save". You're done. Whew!"

link: http://visibility.tv/tips/color.html