UIColor to image, using Perl and ImageMagick. This is just scary ugly. Next time I'll do it with Cocoa.

uicolor-to-image.pl

#!/usr/bin/perl

use strict;
use warnings;

my $token;
my @tokens;
my ($num, $denom, $value, $hexcolor);
my $outfile = "result.png";

# don't require the user to quote the argument string
while (defined($token = shift)) {
    push(@tokens, $token);
}
my $line = join(' ', @tokens);
my $orig = $line;

die "usage: $0 [UIColor colorWithRed:...]\n" if ($line =~ m{^\s*$});
die "error: not overwriting existing file $outfile" if ( -e $outfile);

# strip off any trailing 'f' from float, and add 0 if missing
$line =~ s{(\d+)\.(\d*)(?{$denom=($^N)?$denom=$^N:$denom="0"})f?}{$1.$denom}gi;

# extract float values, perform division, and rewrite the result as hex strings
# could redo this and the next if to be combined, but readability is already an issue here
$line =~ s{(\d+\.\d+)(?{$num=$^N})/(\d+\.\d+)(?{$denom=$^N})(?{$value=sprintf("0x%02x", (255*$num/$denom))})}{$value}gi;

# extract the hex value strings and build a hexcolor
if ($line =~ m{colorWithRed:0x(\w+)\s+green:0x(\w+)\s+blue:0x(\w+)\s+alpha:(\d+\.\d+)(?{$value=sprintf("%02x", $^N*255)})}) {
    $hexcolor = '#' . $1 . $2 . $3 . $value;
}

if ( ! defined($hexcolor)) {
    print "unable to parse string >>$orig<<\n";
    print "result after rewriting was >>$line<<\n";
    exit -1;
}

`convert -size 480x640 xc:"$hexcolor" $outfile`;