Warning color

Warning sign W05:
"Warning of radioactive substances or ionizing radiation"

The colors red (also in connection with white ), yellow and orange (in combination with black ) are called warning colors , because people usually notice them as signal colors . They appear in isolation and in combination with one another. Barrier tape or paint in front of sources of danger (steps, construction pits) are therefore yellow-black, as are the signs for radioactivity and dangerous goods.

Hazard symbol: Very toxic (T +)

Traditional warning colors are linked to the respective cultures and deviate from European conventions outside of Europe. The color yellow is the international identification color for hazardous substances.

Next to yellow, the most common warning color used is red as it is one of the most noticeable colors . For example, the stop signal from traffic lights is red, as is fire engines from the fire brigade . Prohibition signs have a red border or are completely red like the stop sign . The combination of red and yellow, the color orange is used as a warning color, so most of the hazard symbols have an orange background.

Warning colors in nature

Warning colors are also used in nature. While some animals hide themselves and even imitate objects of their habitat to perfection (mimetics), there are also those who, quite the opposite, rely on being seen. Most of them are poisonous, inedible or defend themselves e.g. B. with spines. To minimize the need for resistance, these species typically wear yellow-black or red (-black). This protective tactic is called aposematism . Once a herbivore gets to such an animal, it is quickly conditioned to associate this color with the associated unpleasant experience. In some cases, predispositions to avoid warning colors are also innate. Not all species rely solely on their warning colors. For example, some frog and tail amphibians have the toad reflex . In a dangerous situation they turn on their backs and only present their colored belly in this position.

However, completely harmless animals such as the hover fly , which imitates the typical yellow-black pattern of the apoidea , also benefit from it . This false warning color is mimicry . It works as long as the defense of the aposematic species outweighs the profit of the mimicry hunting species.

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  Real wasp

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  Young of the fire-bellied toad

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  fire salamander

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  Strawberry frog

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  Colorado potato beetle

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  Toadstools

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  Antennae lionfish

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  Texas coral otter

Individual evidence

1. ↑ Peter Kappeler: Behavioral Biology . Springer-Verlag, 2016, ISBN 978-3-662-53145-7 ( google.ca [accessed on July 13, 2018]).
2. ↑ Peter Kappeler: Behavioral Biology . Springer-Verlag, 2016, ISBN 978-3-662-53145-7 ( google.ca [accessed on July 13, 2018]).
3. ↑ Toad reflex . ( Spektrum.de [accessed on July 13, 2018]).
4. ↑ Peter Kappeler: Behavioral Biology . Springer-Verlag, 2016, ISBN 978-3-662-53145-7 ( google.ca [accessed on July 13, 2018]).