Wire Nut Sizes by Color. Standard wire nuts come in five main sizes, which are usually color-coded to show the ranges of wire gauges— or wire thicknesses, measured in AWG— that they can be ...

Choose the correct nut: Before starting a project, have the right type and size wire nuts on hand. Read the label. Make a fresh cut: Snip off the ends of the wires you're splicing with wire strippers.