And, U.S. and international copyright treaties allow you to download files from Web pages. However, those U.S. and international rules control how you use the files. Transparent GIFs To make an image blend into the background on a Web page, make the .GIF image file transparent. That is, make the background color of the image match the background color of your Web page as closely as possible, then make that background color the transparent color in the .GIF image. Small buttons Keep buttons, icons and other small graphics for a Web page under 5K. That way, on a 28.8 Kbps modem connection, each graphic will load in a second or less.
Small graphics Make images small and, therefore, fast to download.
Reducing the number of bits per pixel lowers the size of the file. Dithering means simulating colors on a computer screen by putting pixels of different colors together. Most computer operating systems offer 216 colors which will not dither. Use the 216 colors for a clean, even look on your Web pages. In fact, most are .GIF images.