how to validate hexadecimal color code in php

When taking Hex color code as an input from user it is necessary to validate it. We can validate using preg_match function in php which returns 1 if matches found else 0 using following code.

if(preg_match('/^#[a-f0-9]{6}$/i', $hex_color))
{
//color code is valid
....
}
else
{
//Invalid code
....
}