This article aims at performing - on the basis of cognitive linguistics - an analysis of idioms which are related to the concept of “colour” both in Spanish and in Polish. Various Polish and Spanish idiomatic expressions are examined with the focus on determining what colours are used and in what sense - literal, metaphorical, or metonymical. The comparative analysis of “colour” idioms in both languages is conducted. There are many linguistic expressions which use the colour “black” as a metaphor of the negative aspects in both languages. However, despite the tendency to perceive the colour “white” as the opposite of the colour “black,” such juxtaposition has been observed neither in Polish nor in Spanish. The expressions containing the colour “black” usually conote the negative, whereas the expressions with the colour “white” as a symbol of goodness or the positive are very rare.