The ColorSpace class is an abstract class. It is expected that particular implementations of subclasses of ColorSpace will support high performance conversion based on underlying platform color management systems. However, most developers can simply use the default sRGB color space or color spaces that are represented by commonly-available ICC profiles, such as profiles for monitors and printers or profiles embedded in image data. ICC profiles describe an input space and a connection space , and define how to map between them. Transparency defines the specular transmission of light through transparent materials, such as glass, or the lack of transparency for completely opaque objects.
Images can carry transparency information, known as the alpha channel, for each pixel in the image.
The alpha value is particularly important when colors overlap. The alpha value specifies how much of the previously-rendered color should show through. The Java Transparency interface defines the common transparency modes for implementing classes. Table  5-2 lists the variables used to specify transparency. The data are treated as having no alpha channel, i.e., all bands are color bands.