Yellow is considered to be a warm colour within the colour spectrum, along with reds and oranges. When you are trying to pair mustard yellow with another colour, you should consider your options thoroughly before you make your final choice. Whether you are choosing complementing colours for your wardrobe or walls, adding another colour can tie it all together or ruin the aesthetic appeal.
Black pairs well with almost any colour. The only set of colours that is not complemented by black are pastel colours. If you are working with bright mustard yellow, black would work well with it. If you are working with lighter mustard yellow, you may want to go with another colour.
Violet is a direct complementing colour to yellow on the colour wheel. Consider the shade of mustard yellow before you pick your violet. A darker shade of yellow goes better with a darker violet.
Chocolate brown pairs well with a lighter, creamy mustard yellow. This rich, earthy tone complements the softness of this shade of yellow.
Fuchsia and magenta are desirable berry colour choices if you are working with an earthy tone of mustard yellow. The key to this pairing is to make sure the shade of yellow is the same shade of a berry tone. In other words, use the same level of lightness or darkness of the colour.
A shade of purplish-blue pairs well with some shades of mustard yellow. As with other colour pairings, it is important to keep the shades of the two colours the same. A darker blue goes better with darker yellow.