Repeat diagrams for,color and wea e effects in two colors that have both colors in every row and column can be obtained from weave diagrams representing one fabric laid on top of another. A very simple relation is found between the fabric layer in which a thread will occur in such a weave diagram and the color that has to be assigned to it for an effect repeat to be identical to that weave diagram. In general only this one arrangement of yam colors can give the required effect, and there are always weaves with which it c be realized. Some characteristics of such effects are then considered.