Have you ever heard about superstition in your life? Every country has many different superstitions. When I was thinking about this, I couldn't imagine that some people believe and some people don't believe that there are superstition for number and colors.
First, some people think that number can be good luck and bad luck. In fact, in Iran people think the number 13 is not lucky for them. In Iran people don't like to have the number 13 as the number of their house. Some people put 12+1 instead of 13 for their house number. Accordingly they don't like to have a house with this unlucky number. Likewise in Japan people believe the number 7 is lucky for them. Therefore people prefer to have the house or apartment with this number or to have a hotel room with this number. Accordingly Japanese people they prefer to get house or apartment number or even get license plate for car or phone number have number seven on it. Superstition of number can be lucky and can be unlucky for every country.
Second, there are some superstition color effect people to buy something and some people to ignore to buy them because they can be lucky and they can be have opposite way. People from China they think white color can be bring lucky for them. Accordingly people are likely to buy thing with white color. For example when they want to buy car they prefer to buy white car. This also cause increase the price in china for the thing with white color especially white car. Even this can affect people to wear white wedding dress for the day of weddings. Moreover in some country such as Iran people them afraid of yellow color because they think this color can be unlucky for them and have unpleasant for them. For example if the person wants to give flower to his wife or anyone to show the love it better to get the person any kind of color except yellow because this color shows hate. Also if they want to buy dress for someone as a gift in fact they will not buy yellow again because it can bring unlucky for them and this cannot be a good gift. Superstition of color may have a positive mining and may have negative meaning for every culture.
Overall, there are a lot of superstition such as number and color in every country with deferent meaning. My suggestion is to just focus on your brain and believe anything you think is make sense in your mind because we have a lot of superstitions around a world so it is impossible to focus on every superstition.