Mitsubishi/OSRAM have discontinued their entire colored fluorescent bulb lineup in his formfactor. Unfortunately this means that the bulb has no functional replacement. Fortunately, the way these bulbs are designed has the ballast and the starter in the bulb itself, meaning that the GX10Q adapter takes 110V in. It can therefore be adapted to other bulb formfactors fairly easily, or you could use white cfl bulbs in that formfactor, like the FDL18LE, and wrap it in a gel filter. Additionally there are white LED bulbs in the FDL formfactor should you choose to go that route, again needing a gel filter.