in house hold wiring what is colour of earth wire
Electrical wiring In the United States, color-coding of three-phase system conductors follows a de facto standard, wherein black, red, and blue are used for three-phase 120/208-volt systems, and brown, orange, and yellow are used in 277/480-volt systems. In buildings with multiple voltage systems, the grounded conductors (neutrals) of both systems are required to be identified and made distinguishable to avoid cross-system connections. Most often, 120/208-volt systems use white insulation, while 277/480-volt systems use gray insulation, although this particular color code is not currently an explicit requirement of the NEC.[3]
Flag of the United States The exact red, white, and blue colors to be used in the flag are specified with reference to the CAUS Standard Color Reference of America, 10th edition. Specifically, the colors are "White", "Old Glory Red", and "Old Glory Blue".[64] The CIE coordinates for the colors of the 9th edition of the Standard Color Card were formally specified in JOSA in 1946.[65] These colors form the standard for cloth, and there is no perfect way to convert them to RGB for display on screen or CMYK for printing. The "relative" coordinates in the following table were found by scaling the luminous reflectance relative to the flag's "white".