Resistors have a wattage rating. Wire wound resistors have their value written on them. The Resistor Colour Code allows to read the values of resistors. The procedure is as follows. You should ignore the colour of the resistor body.
Most resistors have three coloured bands close together at one end and one single band at the other.
The three adjacent band give the resistor value. The band nearest the wire lead gives the value of the first digit. The third band gives the number of zeros which follows the two digits.e.g. A green blue black resistor would be 56 ohms. Electric shock is a major hazard.