This type represents a DOM element's attribute as an object. In most DOM methods, you will probably directly retrieve the attribute as a string (e.g., Element.getAttribute(), but certain functions (e.g., Element.getAttributeNode()) or means of iterating give Attr types.
A CSSMatrix represents a homogeneous 4x4 matrix to which 2D or 3D transforms can be applied. This class was allegedly part of CSS Transitions Module Level 3 at some point, but is not present in the current Working Draft. Use DOMMatrix instead.
color is a CSS media feature whose value is the <integer> number of bits per color component (red, green, blue) of the feature. CSS colors can either be defined in hexidecimal format or in an RGB format.