3 Phase Coloring

Because if you wire red to yellow and black to blue you let out the ominous smoke from the appliance which is called the soul of the device and it will not work furthermore. You also could let some real souls go fly away if the wiring is not as per the color code!

If red was yellow then yellow would have to be red!

In final words - the question is not what color it has but if it is in the right place.

Try another version and get four grey cables . . . and you get the meaning of the colors.

If it was me I would paint it pink or violett but it is hard to get the insulation back on afterwards . . .

It was decided by the IEE Regulations board, for standardisation.

Although i don't know if there are differences in wire colors in different countries

Yes Ok! Thats probably more it!

Build control panels for equipment that goes to Europe and a lot of Asia:

Brown Black Grey Blue (Neutral) Green/Yellow (PE)

The different colors, whatever they may be, are so that in a distribution system, you always know which phase is which when you look at connections and if you remove them for servicing, you can reconnect them the same way so that motors do not run backward. What colors to use are dictated by local codes and usually correspond to voltage levels.

As for any coding, Identification. When i worked in the electrical trade. In practice low voltage(-480V 3Ø) is black, red , blue and high voltage(+480 3Ø) brown, orange, yellow.

Other than phasing on equipment. Load distribution in lighting.

The UK changed from Red, Yellow, Blue with Black for neutral to Brown, Black, Grey with Blue as neutral. It's been chaos ever since.

Yes - you "chaps" have that comination as does most of Europe, Singapore and China. The part I really like about it is the European produced small signal cables have what colors in them? Why Brown, Black, Blue, Grey, and White. The most used are lines 1 and 3, which are usually the conductors for the 24VDC, and they are brown and blue. Just love having 24VDc on the same colors as an AC voltage phase and neutral. Makes things easier to figure out in a control panel where you have a VFD and 4-20ma control signals.

So you can tell them apart

all the sexy colors were taken

Red, Yellow & Blue take probably they are fluorescent colours and attracts eyes, and easier to find even sometime in little dark because of color. For some other color in little dark all could look somewhat similar color and hard to differentiate what phase it is. You can compare with like waring yellow helmet in construction site.

Historical.

Red, yellow and blue are the three "primary colours", and were standard until the latest revision of BS7671 came out. Installations from 2004 onwards, or thereabouts, will have brown/grey/black with blue as a neutral under the latest revision of the standard.

The standard was changed to bring the UK into harmony with the rest of Europe.

There are a lot of installations where both versions of the colours are in use. It is confusing, and the typical British compromise of sticking a label on the distribution board does little to eliminate that confusion. Thank goodness for fuses!

Do Color blind people have problems with this, i wonder.

It is time to have a common color/numeral code for electrical wiring for phases,neutral, earth,positive,negative etc for each rated voltage(AC & DC) and for power,control & measuring circuits all over the world to avoid confusion.