Create color list file (.clr) used for Apple color pallet, stored in ~/Library/Colors

create_color_list.m

#import <AppKit/AppKit.h>

int main(int argc, char *argv[])
{
    @autoreleasepool {
        NSColorList *colorList = [[NSColorList alloc] initWithName:@"Colors"];
        if (argc < 2) {
            printf("Usage: %s name:rrggbb,name:rrggbb,...\n", argv[0]);
            return 0;
        }
        NSString *colors = [NSString stringWithUTF8String:argv[1]];

        for (NSString *colorString in [colors componentsSeparatedByString:@","]) {
            NSString *key;
            NSArray *keyAndColor = [colorString componentsSeparatedByString:@":"];
            if ([keyAndColor count] > 1) {
                key = keyAndColor[0];
                colorString = keyAndColor[1];
            } else {
                key = [NSString stringWithFormat:@"#%@", [colorString lowercaseString]];
            }

            NSScanner *scanner = [NSScanner scannerWithString:colorString];
            unsigned int colorInt;
            [scanner scanHexInt:&colorInt];

            CGFloat r = (CGFloat)((colorInt >> 16) & 0xff) / 0xff;
            CGFloat g = (CGFloat)((colorInt >> 8) & 0xff) /0xff;
            CGFloat b = (CGFloat)((colorInt) & 0xff) / 0xff;

            [colorList setColor:[NSColor colorWithRed:r green:g blue:b alpha:1.0f] forKey:key];
        }

        [colorList writeToFile:@"Colors.clr"];
        return 0;
    }
}