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Tuesday, June 19, 2012

Ethernet Patch Cable Colour Codes & Bestpractices

Ethernet Patch Cable Colour Codes

Keeping data from getting crossed in a data center can be a pain. Below are some of the standards followed in Data Centers
  • blue - most common so workstations or generic servers.
  • red - critical systems. Sometimes used for building fire systems
  • yellow - less critical system.
  • orange - cabels that go off to other racks
  • green - where the money flows for e-commerce systems.
  • black - VoIP systems since the phones came with blakc patch leads
  • white - video camera network
  • pink - used for rs-232 serial cables
  • purple - used of isdn type links
  • tan - telephone lines  
This is the current list of colors of ethernet cables that can find be found in general ind DC or have seen:

light blue (rare but commonly used on cisco cables)
fluorescent blue (even rarer)
red (many of these are cross over cables)
yellow (this was a standards approved color for cross over cables)
cisco cable yellow
fluorescent pink
fluorescent green (never seen this buts its in catalogs)
black (easy to confused with power cords)
white (sort of rare)
light gray
dark gray (rare)
silver (rare)
tan/beige (common in cat 3 patch cables)
purple/violet (they are different but when you order one you get the other)
fluorescent violet (very rare)

One thing to consider is about 15% of all males are slighly color blind and only about 10% think they are. Many colors look the same but often times a color blind person can easliy tell the difference between say tan cables and beige cables but can't tell the red from the green.

Color codes for fiber (fibre?)

Orange - multimode
Yellow- Single mode
gray - could be either but tends to be single mode
light blue - could be either
Color codes for fiber jackets
Blue - Stright cut - fiber joint is perpeneducalr at 90 degrees
Green - Angled cut - fiber joint is angled slightly

Note that buildings will often have these colors:

red - fire alarm cables
white - cheaper fire alarm cables
blue - who knows? Could be alarm, fire, hvac, or data
tan - same as blue but older

For -48 volt systems you can get:

red - ground.
black - negitive 48V but can routinely be -56V
blue - could be the same as red or black but tends to be the same as red on a differenc circut

Note that -48 Volt systems tend to be able to provide massive amounts of unfused current. These system will often have enough capacity to boil the metal in tools.

That describes the outer jackets. Inside cables like power you can have:

Live power from selected places around the world:


red (power Au/UK)
brown (old for AU/NZ/UK)
yellow (old phase 2 UK)
blue (old phase 3 UK)
blue (phase 3 in AU)
blue neutral in Europe
black (power in Europe)
Gray (old IEC phase 3)
gray (power Europe)
gray (neural in US/Japan)
white (neutral in US)
white (pahse 2 in Au)
white (swtich return in AU/UK)
green/yellow - Ground most places
green or yellow but not both (power IEC 60446 and a bad idea)
green (ground in the US according to parts of the Elec code)
green (Never ground in the US according to parts of the Elec code)
bare copper (ground in the US or death)

The color codes for ships make much more sense and are about as uniform. For example blue is used for compressed air on US registered ships yet blue is for water on UK registered ships.



  1. At my company we have found that it is actually cheaper just to buy patch cables because the cable heads are expensive.

  2. in ethernet cable 10Base2 networks utilised 50 ohm impedance coaxial cable that was much thinner and more flexible than 10Base5, but the Ethernet signals were still designed to be transmitted over this medium at 10 Mbps,


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