Exercise 5: Using Color; Understanding Color Indices; Understanding Color Definitions - Tektronix 4106 Operator's Manual

GETIING ACQUAINTED
EXERCISE 5: USING COLOR
In this exercise you will learn to change colors using the terminal's Interactive Color
Interface. (If you are doing this exercise out of sequence , do Exercise 1, then do
the steps in Creating a Panel Within a Segment and Creating Two Panels Within a
Segment in Exercise 4.)
UNDERSTANDING COLOR INDICES
Every color you can display is identified by a number called a color index. To select
a color for text or a graphics element , you assign a color index to it.
Before creating your graphics in Exercise 4, you used the command
DAINDEX 0,3,3 to select the color indices for the dialog area. These indices
specified black text (Index 0) , in green character cells (Index 3) , on a green
background (Index 3) . (A character cell is the rectangular area surrounding each
character.)
Later, to let your graphics show through the dialog area, you changed the dialog
area color indices to display green characters (Index 3) , in transparent character
cells (Index 0) , on a transparent background (Index 0) .
In both of these cases , when you changed colors , you specified a new index
number. The colors assigned to each index are :
0 -
Transparent
1-White
2-Red
3 - Green
4-Blue
5 - Cyan
6-Magenta
?-Yellow
UNDERSTANDING COLOR DEFINITIONS
The Set Color function offers another way to change colors . Instead of changing
index numbers , you can change the color definition assigned to an index. For
example , you could change the color definition assigned to Index 2 from red to
yellow; then , every part of an image that uses Index 2 would become yellow.
Using the Set Color function , you change colors by using special function keys ,
rather than entering commands.
The Set Color function gives you three methods for changing color definitions. In
this exercise you will use all three methods so you ' ll be familiar with the advantages
and limitations of each one . Here 's what you ' ll learn in this exercise :
• First, you 'll learn how to change a color definition by replacing it with a color
definition chosen from a color menu .
• Second , you ' ll learn how to change a color definition by changing its hue,
lightness, and saturation (HLS) values.
• Third , you ' ll learn how to display the terminal's complete color map and modify
any color definition shown there .
You'll see that in all methods the color changes , but the index number remains the
same .
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4106/4107/4109 OPERATORS