Resistor colour codes

3/4/5/6 bands possible.

A gap separates that last band from the rest so that we can know which is the first band.

Reference: NCERT Class X Science textbook (Physics)

Colors

From IEC60062:

Colour Significant Multiplier Tolerance TCR
numeral (%) (10⁻⁶/K)
Black 0 1 - 250
Brown 1 10 ±1 100
Red 2 10² ±2 50
Orange 3 10³ ±0.05 15
Yellow 4 10⁴ ±0.02 25
Green 5 10⁵ ±0.5 20
Blue 6 10⁶ ±0.25 10
Violet 7 10⁷ ±0.1 5
Grey 8 10⁸ ±0.01 1
White 9 10⁹ - -
Gold - 10⁻¹ ±5 -
Silver - 10⁻² ±10 -
Pink - 10⁻³ - -
None - ±20 -

4 band

    +----------+
    | █ █ █  █ |
----+ █ █ █  █ |----
    | █ █ █  █ |
    +----------+
      A B C  D
Band Significance
A First significant value
B Second significant value
C Power of 10 multiplier
D Tolerance

Eg: 470Ω is

4: Yellow 7: Violet 2: Red