Browser Color Capabilities Netscape displays 216 colors, each of which is identified by hexadecimal code in the table below. These colors are recognized by Netscape as background or text colors, and also display properly when viewed as part of a graphic image. Many designers will save graphics in 8-bit mode, closest to the actual number Netscape can display to avoid loss of color clarity. The JPEG image format was developed by the Joint Photographic Experts Group as an early standard for computer graphics combining image clarity and efficient file sizes, and remains the most popular choice for scanned and digital images. JPEG is not ideal if you need to repeatedly edit and recompress an image once saved, but does provide adequate clarity for images saved once.
Bit depth is defined by the number of bits per pixel which display on a screen.
A 1 bit display or graphic is a black and white image, a 4 bit image displays 16 colors, an 8 bit image displays 256 colors, and a 24 bit graphic displays 16.7 million colors. The image bit-depth was reduced using GraphicConverter 2.5 on a Macintosh , reducing the colors for each of five new images from the original. Differences between the images are most evident when viewed on a monitor capable of displaying millions of colors. There is little discernible difference between the 24 and 16 bit images, which are both about 7k. Comparing the 16 and 8 bit images we find little degradation in image quality for this photograph.