make color optional

diff --git a/gpio.pl b/gpio.pl
index 55be687..4b68965 100755 (executable)
--- a/gpio.pl
+++ b/gpio.pl
@@ -16,6 +16,7 @@ my $opt_zebra = 0;
 my $opt_lines = 0;
 my $opt_read = '';
 my $opt_pins = '';
+my $opt_color = 0;
 GetOptions(
        'svg!' => \$opt_svg,
        'alt!' => \$opt_alt,
@@ -28,6 +29,7 @@ GetOptions(
        'lines!' => \$opt_lines,
        'read=s' => \$opt_read,
        'pins=s' => \$opt_pins,
+       'color' => \$opt_color,
 );
 
 # svg font hints
@@ -208,6 +210,9 @@ swap_cols 'txt' if $opt_invert;
 
 sub svg_style {
        my ($name,$x,$y,$col) = @_;
+
+       return '' unless $opt_color;
+
        $y -= $font_b; # shift box overlay to right vertical position based on font baseline
 
        sub rect {