An article by Faber Birren, the second of three on color in textile design, explaining optical illusions that affect how colors look in woven and printed fabrics. It covers the after-image (the opposite color the eye generates), how it shifts adjacent colors, and fixes such as adjusting dye tones or outlining color areas. It also discusses advancing and retreating colors, the effect of dull backgrounds on pure colors, and the diffusion of analogous colors in woven threads, including changeable silks, to gain brilliance or achieve harmony.