色彩深度计算机图形学领域表示在位图或者视频帧缓冲区中保存1像素的颜色所用的位数，它也称为位/像素（bpp）。色彩深度越高，可用的颜色就越多。

色彩深度是用「n比特颜色」（n-bit colour）来说明的。若色彩深度是n比特，即有2种颜色选择，而保存每像素所用的比特数目就是n。常见的有：

另外有高动态范围影像(High Dynamic Range Image)，这种影像使用超过一般的256色阶来保存影像，通常来说每个像素会分配到32+32+32个bit来保存颜色信息，也就是说对于每一个原色都使用一个32bit的浮点数来保存.

Color depth, also known as bit depth, is either the number of bits used to indicate the color of a single pixel, in a bitmapped image or video frame buffer, or the number of bits used for each color component of a single pixel. For consumer video standards, such as High Efficiency Video Coding (H.265), the bit depth specifies the number of bits used for each color component. When referring to a pixel the concept can be defined as bits per pixel (bpp), which specifies the number of bits used. When referring to a color component the concept can be defined as bits per component, bits per channel, bits per color (all three abbreviated bpc), and also bits per pixel component, bits per color channel or bits per sample (bps). Color depth is only one aspect of color representation, expressing how finely levels of color can be expressed (a.k.a. color precision); the other aspect is how broad a range of colors can be expressed (the gamut). The definition of both color precision and gamut is accomplished with a color encoding specification which assigns a digital code value to a location in a color space.