Resistor color codes, standardized in IEC 60062, specify electrical component ratings, primarily for resistors.  A typical four-band resistor uses color bands to represent significant figures (first two bands), a multiplier (third band), and tolerance (fourth band).  For example, green-red-blue-gold translates to: green (5) and red (2) for significant figures, blue (1,000,000) as the multiplier (resulting in 52,000,000 Ω or 52 MΩ), and gold (±5%) for tolerance (49.4 MΩ - 54.6 MΩ).  Variations exist; military-spec resistors might include a fifth band for reliability, while five-band resistors offer higher precision with a third significant figure band, shifting the multiplier band's position.  Other bands can indicate temperature coefficient.