Aluminum indium gallium phosphide (AlInGaP) is the semiconductor material used for the 565nm to 645nm range. It is predominately used for traffic signal yellow(590nm) and red (625nm) lighting. The lime green (or yellowish-green 565nm) and orange (605nm) are also available from this technology, but they are somewhat limited. The technology is rapidly advancing on the red wavelength in particular because of the growing commercial interest in making red-green-blue white lights. It is interesting to note that neither the InGaN or AlInGaP technologies are available as a pure green (555nm) emitter. Older, less efficient technologies do exist in this pure green region, but they are not considered efficient or bright. This is due largely to a lack of interest and/or demand from the market place and therefore a lack of funding to develop alternative material technologies for this wavelength region.