Question

Why there are two Color constants defined in java.awt.Color class? For instance

public static final Color blue;
public static final Color BLUE;

This is obviously redundant. Is there some specific usage scenario – like a best practice where upper case Color is preferred over lower case Color or vice-versa ?

Answer 1

It’s a naming convention thing.

Java originally defined a few color constant names in lowercase, which
violated the naming rule of using uppercase for constants. These are
best to use since they are available in all versions of Java:
Color.black, Color.darkGray, Color.gray, Color.lightGray, Color.white,
Color.magenta, Color.red, Color.pink, Color.orange, Color.yellow,
Color.green, Color.cyan, Color.blue

Java 1.4 added the proper uppercase names for constants: Color.BLACK,
Color.DARK_GRAY, Color.GRAY, Color.LIGHT_GRAY, Color.WHITE,
Color.MAGENTA, Color.RED, Color.PINK, Color.ORANGE, Color.YELLOW,
Color.GREEN, Color.CYAN, Color.BLUE

Source