What has skin colour got to do with the way you act? It's not a culture how can you act a skin colour.
Basically be aware that your personal experiences as say a middle to upper class white person may not reflect those of people with different backgrounds*? or even that someone from the same general background as you, but who say grew up and was educated in a different part of the country may have different experiences.
It's a very clumsy way to put it, but it's very much worth noting as for example if you do your advertising across a region based on a sample from one group you can end up with something that is offensive/doesn't work for other groups, for all sorts of reasons some as simple as different names for the same thing (look at the bap/bun/bread roll usage in the UK).
The story about how Dyson got his bank loan initially is a great example, bank managers were at the time, typically white men who didn't usually do things like vacuuming, so their view of a guy asking for a loan to develop a better, easier to use vacuum cleaner was quite different to what someone who used one on a regular basis and had to cope with the issues involved might have had**. IIRC the bank manager asked his wife (or so the story goes) what she thought of this proposal and because she could see the benefit he approved the loan, a manager who didn't ask that advice may not have done so (and I believe he mentions having been turned down repeatedly by bank managers who didn't understand the subject and didn't look further for opinions).
Or if you have your product testers as a people from one ethnic group you end up with things like automatic hand driers that don't work in low light if you've not got the right skin colour as they're not calibrated to allow for that which results in a product that can get a reputation for being very unreliable or need a recall/service to adjust the sensor which is far more expensive than simply making sure your testing group is more diverse (or at least aware of the limits of the test group) ), or and this is a huge one if say you base all your crash testing on the average adult male body you end up with safety features that don't work as well, or are actively harmful for say women, or younger people (an issue that is only now being fixed).
Or for example knowing that in different areas people have different tastes, or sensitivities so you don't go and waste a fortune trying to sell something that tastes "wrong" to people in an marketing area.
It's one of the reasons a lot of the most successful companies tend to get people from all sorts of backgrounds involved in marketing and product development and testing, and in the most obvious cases you hire a local firm who know the market to assist in product development and launches outside of your home market.
Basically don't assume what you experience is the same for everyone.
*IIRC General Motors and Ford were doing that ~60 years ago, they very specifically had entirely different brands targeted at different parts of the market, with different marketing teams as they knew that say the "upper management" wanted slightly different things from their car than say "blue collar joe" working on a production line or construction, and as a result even the language used in the manuals and brochures varied.
**As someone who in the 80's and 90's was the one who had to sort out the vacuum for my mum, then neighbours/family my first experience of a dyson was disbelieve, a vacuum that if it got blocked didn't require at least one screwdriver (often two or three, maybe an allan key as well), and a wire coathanger to clear blocks, or replace the belt. Compared to the Hoovers, Electrolux and Panasonics I was used to it was a positive joy and so simple to sort out and what had been a regular job that could take 15-30 minutes was now a 2 minute job that only required a tuppence for two latches.