0 Gray
8
Blue
1 Gold
9
Light blue
2 Orange
10
Turquoise
3 Red-orange
11
Green-blue
4 Pink
12
Green
5
Purple 13 Yellow-green
6
Red-orange 14 Orange-g reen
7
Blue
15 Light orange
The remaining 112
colors are obtained by adding a value for
luminance, or brightness. The luminance must be
an
even number
between
0 and 14. The higher the luminance number, the lighter and
brighter the
color.
Color
registers are another important element
in
ATARI graphics. The
color registers can be thought of
as
paint cans. Each register can hold
any of the 128 colors. Because there are five registers, a maximum of
five different
colors can be displayed. The five
co
lor registers are
numbered
0,
1,
2,
3,
and 4.
SETCOL
OR
is
an
essential graphics command. The format is
SETCOLOR 2,10,8: the
fi
rst number is the color register; the second
is
the color number; and the third
is
the luminance.
Graphics Mode 0
The color registers function differently
in
different
graphics modes.
Their functions
in
graphics mode 0 (the text mode) are shown in the
chart
below:
Default Colors
Register Function
0
Not used
Li
ght blue 1
Brightness of text
Dark
blue 2
Background
3
Not used
Black
4 Border
The
default
co
lors are the colors that the
computer
automatically uses
unless you instruct it to use some other
co
lors. Using SETCOLOR to
change
colors, type
in
the following:
SETCOLOR
2
..
3
..
4
When you press [ Return I, the screen turns orange. The
co
lor transfor-
mation
occurs
because
in
the SETCOLOR command, the 2 represents
the screen color, the 3 equals the color orange, and the 4 indicates
the brightness. Change the 4 to
2
6.
The orange changes to a lighter
orange. Change the 6 to a 7. Nothing happens because
on
ly the even
69
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