I need to touch up a lower plastic Sacco panel on my W201. Main body colour is 744 Brilliant Silver. Phoned the dealer to get the paint code for the Sacco panel and was given 7738 Sato grey. Got this paint mixed by my local trade paint supplier, who I've used on numerous occasions and their paint mix is usually very good. Tried a colour match on an offcut piece of plastic before spraying, just to be on the safe side and the paint is much lighter than it should be. I know it will need lacquer afterwards, but seems pointless spraying the sacco panel only to find it's completely the wrong colour.
Can anyone suggest what the correct colour might be, please? My nearest M-B dealership is a two hour round trip.