I've been "building" a 67 Impala for what seems like ages now, so I know where you're coming from.
To be honest, I'm personally not a great fan of stock colours, though I can certainly see why a great many people choose to stick to them. Given the amount of chrome and embellishments on this beauty, were I rebuilding it, I'd opt for a dark midnight blue body colour with a powder blue leather interior. Or something dramatic, in two tones. Perhaps black above the "waistline" of the car...with a white bottom half. And do up the interior in black leather. Just my two cents, of course. Mid blue and grey would appear nice, as well. Best of luck!