php颜色值转换 php实现16进制数字与颜色值的转换

/**
* 颜色值与16进制数字的转换
* edit: WWW.JBXUE.COM
*/
function toHex($N) {
    if ($N==NULL) return "00";
    if ($N==0) return "00";
    $N=max(0,$N);
    $N=min($N,255);
    $N=round($N);
    $string = "0123456789ABCDEF";
    $val = (($N-$N%16)/16);
    $s1 = $string{$val};
    $val = ($N%16);
    $s2 = $string{$val};
    return $s1.$s2;
}
//颜色值转换为16进制数字
function rgb2hex($r,$g,$b){
    return toHex($r).toHex($g).toHex($b);
}
//16进制数字转换为颜色值
function hex2rgb($N){
    $dou = str_split($N,2);
    return array(
        "R" => hexdec($dou[0]),
        "G" => hexdec($dou[1]),
        "B" => hexdec($dou[2])
    );
}
echo rgb2hex(106,48,48);
echo ' ';
print_r(hex2rgb("6A3030"));
?>