This paper reports on the colorimetric properties of natural dyes from madder and weld plants. For both crops, a comparison is made among several individual dye compounds and the total plant extracts. Dyeing properties, colour properties and colour stability have been studied. Insight has been gained into the role of the major dye compounds present in the plant. For madder as well as for weld, the use of the total plant extract is considered to be advantageous over the use of individual dye compounds in terms of solubility, colour tone and stability towards light, and non-coloured components present in the plant extract are considered to be responsible for increasing the solubility and the stability of the dye compounds.