Entity color

The color determines how an entity displays on screen and how it prints. Entities are created in the current color, as defined by the CECOLOR system variable.

You can choose between 255 index colors or define a true color.

Index colors

Index color is the specification of the color of a pixel on a display screen using a an 8-bit color value, allowing up to 256 possible colors.

Each of the Index Colors has a unique number from 1 to 255. Seven of the index colors can also be referred to by name: red (1), yellow (2), green (3), cyan (4), blue (5), magenta (6) and white/black (7). Index color 7 displays white on a black screen background and black on a white screen background. Index color 7 always prints in black.

The two additional color properties are ByLayer and ByBlock. These color properties cause an entity to adopt the color either of the layer or of the block in which it is a member. ByLayer is color number 256, and ByBlock is color number 0. In all commands where you would use a color, you can indicate ByLayer and ByBlock as well as by numbers 256 and 0, respectively.

The options to set the Color are:

  • ByLayer: Entities adopt the color of their layer. This allows you to change the color of all such entities by adjusting the color of the layer.
  • ByBlock: Entities are drawn in index color 7 (black or white, depending on the screen background color). When included in a block definition, such entities adopt the color of the block when you insert the block into a drawing.
  • Index Color
  • True Color
Note: Whether entities using an index color will print in this color, depends on the Color Table (CTB) or Style Table (STB) that is used for printing. Only if the Color setting in the CTB or STB definition file is set to Use Object Color, the printed color matches the entity color.

True colors

True color is the specification of the color of a pixel on a display screen using a 24-bit value, which allows up to 16 777 216 possible colors.

The number of bits used to define a pixel's color shade is its bit-depth. True color is also known as 24-bit color. Some new color display systems offer a 32-bit color mode. The extra byte, called the alpha channel, is used for control and special effects information.

True colors use a RGB (Red, Green, Blue) color definition. Each of these parameters has a range from 0 to 255. The RGB definition for black is (0,0,0), the RGB definition for white is (255,255,255).

Setting the current entity color

  1. Do one of the following:

    • Launch the COLOR command.
    • Click the Select Color tool button () on the Settings toolbar.
    • In the Properties panel, select Color, then choose Select Color in the drop down list.
    • Double click the Color Field in the Status bar.

    The Select color dialog box displays.

  2. (option) Click the Index Color tab, then do one of the following:

    • Click one of the colored tiles.
    • Type the color number in the Color Number field.
  3. (option) Click the True Color tab, then do one of the following:

    • Click the in Color Selection pane.
    • Set the color parameters in the Color Parameter fields.
  4. Click the OK button to confirm.