Flower colors of a particular species can vary considerably based on various conditions. For example, when a hydrangea is grown in acidic soil, it will produce pink flowers. If the soil is alkaline, it will produce blue or purple flowers. Also, many species are cultivated to produce different colored flowers that can run the entire spectrum. To further complicate the matter, some flowers will display two or more colors on the same plant. For the purpose of being able to identify a flower by color, we have assigned a Primary and Secondary color to all plant flowers as chosen by their most common natural form. A secondary color can be a 2nd color within the same flower or an alternate hue for a different form or cultivar.