The color of clothing is directly related to the absorption of solar energy. This is why people choose lighter colored clothes in warmer climates. Wearing darker colors generally makes you get warmer, faster while wearing lighter colors helps you stay cooler, longer.
Another example regarding the same concept is houses. Houses in warmer climates are often white or a very light color. You will rarely see a house in a warm climate that is dark. This is because the house will absorb the heat of the sun and the inside would become very hot.
If you have heard of the concept of albedo, you should be able to answer this question. Albedo is a term that refers to how much light reflects off of a given surface. The rest of the light that does not reflect off the surface is absorbed into it.
In general, things that are light in color have high albedos and things that are dark have low albedo. That means that dark clothes absorb more light (and heat) and light clothes reflect more. So if you live in a hot climate you would want light clothes so that your clothes don't get so hot.
Albedo in optics refers to how strongly an object reflects the light it receives, especially the light it receives from the sun. When an object reflects most of the light that falls on it, it looks bright and so it has a high albedo. When an object absorbs most of the light that strikes it, it appears dark. Dark objects have low albedos.
It would be sensible for a person living in places which have a warm or hot climate like the equatorial or tropical regions to wear light colored or white color dresses so that these light or white colored dresses could reflect the hot rays and the harmful radiation of the sun. By doing so the person can be cool and comfortable on a hot summer day. When going out on a hot sunny day it is advisable to use a white umbrella to reflect away the heat and the harmful radiation of the sun.
The proportion of light and heat radiations absorbed and reflected by any surface on which such radiations fall is affected by the colour of the surface. White colour absorbs minimum of such radiations and black colour absorbs the maximum. In general light colours absorb less radiations as compared to dark colours.
Because of this phenomenon, light coloured clothes, that absorb less radiations keep a person cooler, as compared to the darker coloured clothes. Therefore, persons living in warm or hot climates may prefer white coloured clothes over dark coloured clothes.