COORDINATING WINDOW COVERING COLORS WITH OTHER ROOM FURNISHINGS IS GOOD DESIGN
One of the first considerations when creating a pleasant coordinated look is to repeat colors used to compliment the overall design. You can choose a color from any lace curtain fabric or for that matter any drapery or curtain fabric that you are using in the room and use it to repeat accents in other furnishings such as sofas, throw pillows, tie bands, vases and such.
If you choose to use lace or sheer material for the drapery or valance material you should choose the shade to compliment the other colors. If the walls or wood work around the doors and windows are white it is best to stay with the white. If they are off white the ecru is most effective. Earth tones generally are complimented by the ecru whereas white enhances the primary colors and pastels.
If you have questions about which color to use it is a good idea to obtain a lace fabric sample of both the white and ecru to hold against your walls and other fabrics. Remember, you are the designer and you need to choose according to your own taste. Beauty truly is in the eyes of the beholder.