How do I match Toyota paint codes with the generic paints on the market today? Thanks!?

I have a silver 1991 toyota pick-up truck. I found the paint code (147) on the door jam but have been unable to find that number on any products in auto stores (like O'reilly Auto). Does anyone have any tips on how to match this paint? I have looked online but I have only been able to find matches back to 1994 models. Thanks a lot for your time and help.|||my answer is try to check it out first on auto repair shop...|||I have a91 pu too I took the gas doar off and went to napa and they mached it perty good