Carrots were originally white or purple in Europe, yet nowadays we cannot conceive of a carrot not being orange.

Cassava is not a native African crop, yet today, around 400 years after it was introduced from South America, the livelihoods of more than 500 million Africans depend on cassava. There are yellow, beta-carotene-producing cultivars in South America. The HarvestPlus Programme is trying to introduce the trait into local African varieties, hoping that these will be acceptable to people used to white varieties.

In some countries rice is made yellow by adding spices, like saffron or curcuma. We hope that the natural yellow to orange colour of Golden Rice will be acceptable to millions of people, especially after recognising its beneficial health effects.

Eating preferences are markedly regional and it can be rather difficult to change long-standing traditions. For example, the colour and size of common beans in Latin America is indicative of the region where these are eaten. Small, black beans are preferred in Central America, while large beans of various colours are eaten in the Andean region. While nutrient content and taste of these beans are comparable it would take a major effort to change people's preferences in respect of the beans' external characteristics.

The capacity of Golden Rice to produce beta-carotene in rice endosperm is not restricted to a single variety, on the contrary the trait can be easily transferred to any variety by simple breeding. In this way any local preferences and adaptations will be catered for. The only difference between a preferred local variety and the Golden Rice bred for that given region will be the colour, which should not be an unsurmountable obstacle. In some regions, where the white colour is very important, additional promotion will be required.