The swelling behavior of calcium dodecyl sulfate (CDS)/water with heptanol and octanol was investigated at 25 degrees C. Both systems form a condensed lamellar phase at a high content of surfactant and cosurfactant and a highly swollen lamellar phase at a low surfactant content. There is no single-phase channel between both lamellar regions. A dilute L-3 phase exists in the heptanol system as well as in the octanol system. This LQ phase is water-like transparent and shows no streaming birefringence. On dilution of samples with an appropriate composition of water, iridescent phases can be obtained which display bright blue to green colors. In contrast to CDS with pentanol or hexanol, the lamellar region is broken into a dilute phase and a condensed phase because of decreasing undulation forces of systems containing longer chain alcohols.