Colour Printing
When printing in colour, the colour number of each element is used to look up the attached colour table. The colour table defines each colour as a combination of Red, Green, and Blue (RGB) values ranging from 0 to 255. The range is usually from 0.0 to 1.0, but since MicroStation stores the value as an integer, 1.0 is represented as 255.
Another system of colour definition, CMYK, defines colours as a combination of Cyan, Magenta, Yellow, and Black ranging from 0.0 to 1.0. RGB colours can be converted to CMYK using a simple process.
If Red = Blue and Blue = Green, then the colour is a grayscale with:
Else:
The following tables describes the typical colour values:
|
Colour |
Red |
Green |
Blue |
Cyan |
Magenta |
Yellow |
Black |
|---|---|---|---|---|---|---|---|
|
White |
1.0 |
1.0 |
1.0 |
0.0 |
0.0 |
0.0 |
0.0 |
|
Red |
1.0 |
0.0 |
0.0 |
0.0 |
1.0 |
1.0 |
0.0 |
|
Yellow |
1.0 |
1.0 |
0.0 |
0.0 |
0.0 |
1.0 |
0.0 |
|
Cyan |
0.0 |
1.0 |
1.0 |
1.0 |
0.0 |
0.0 |
0.0 |
|
Grayscale |
0.4 |
0.4 |
0.4 |
0.0 |
0.0 |
0.0 |
0.6 |
|
Black |
0.0 |
0.0 |
0.0 |
0.0 |
0.0 |
0;0 |
1.0 |
CMY colours can be defined in MicroStation, but CMYK colours can only be defined in the Bentley Advanced Map Finishingg colour table (.CCT files). SeeBentley Advanced Map Finishing Colour Control dialog.
The final output of CMYK colour in separations can be affected by the Under Colour Removal option described in Separations Tab.
Note: Printing the same MicroStation colours on different types of printers produces noticeable differences in the final output. Generally, colours vary in intensity because printers use different inks and processes for laying down the ink. If precise colour selection is required, print a sheet showing all colours in the colour table on all printers to be used. Use the example sheet to select colours.
Changes to the colour table may be required to get the desired colours. A different colour table for each type of printer could be required if compatible colour output is needed. Bentley Advanced Map Finishing includes a design file, COLOURS.DGN, which displays the colours in a table format. Attach the required colour table to this file, change the headings, and print it using Bentley Advanced Map Finishing.