Winsor amp newton cotman water colour 8ml tubes winsor newton 0303660 this ultramarine 660 water colour 8ml tube has been made to winsor amp newtons high standards yet remains economical thanks to the more costly pigments being replaced by less expensive alternatives in the process producing good tinting strength and transparency many of the pigments used in this colour remain organic while artists have the choice of intermixing the cotman water colour with the artists water colour