We'd make a fortune if we could! There's a pesky physics problem here, and it's caused by the fact that our beams of light scatter off of water droplets in the air, including clouds, allowing them to be visible. In order to project any shape, we need to have a known focal distance from the source (our lights) to the object. In the case of clouds, there's no obvious boundary as the moisture levels increase as you move closer to and into the cloud structure. Because of this, if we projected your favorite symbol into the sky the result would be nearly the same as what you get with the columnar beam only with some fuzzy effects that don't look quite like anything at all. Your favorite superhero would be confused, and that's bad for everyone, so the mobile phone is probably the best way to request immediate assistance when some joker or two-faced guy is causing issues in the city.
Unfortunately, not really, due to some guidance from the FAA (see below). Even if we were allowed to use differing colors, the human eye tends to switch to more of a black/white contrast in the nighttime and our perception of color changes. Also, our eyes are more sensitive to particular colors (green) versus others (red), while moisture absorbs and reflects/refracts light differently across the visible spectrum as well. All of this adds up to a situation where it may seem like an exciting effect, but the practical implementation leaves much to be desired in our experiments. We're not going to sell an effect that we're not proud to deliver.
We absolutely care about the safety of all persons, including those in flight. We regularly contact the local FAA office as well as air traffic control towers to notify them of our operations in their areas of control. In some rare cases, a NOTAM (Notice to Airmen) may need to be issued. On occasion, we'll be asked to obtain "authorization" or "approval" from the FAA by a potential customer. Generally speaking, this isn't how the FAA works--there is no formal, regulatory requirement to apply for operating authorization. Instead, they expect that we comply with 18 U.S.C. 32(a)(5) and request a NOTAM be posted when we pose some potential risk to aviators. The punishments for failing to comply with the law are extremely severe (which we support), and we wouldn't be in business long if we posed a risk to those in flight.
Per the FAA guidance we've received: our lights must be white in color, rotation may not be greater than 45° from vertical, and must not intersect the final approach course at an angle which could enter the cockpit and interfere with the flight crew's vision. Our lights are white in color only, our rotation is limited to 22.5° from vertical, and when we are near an airport approach corridor we check the maps closely and provide notification to the Air Traffic Control Tower. We have never been contacted by the FAA or ATC with a request to discontinue operations because they pose a hazard, and this is a point of pride for our business.
Lasers are a different matter entirely, and are regulated by 18 U.S.C. 39A. We do not operate lasers in any form.
We are continually watching the LED technologies evolve, and will likely be early adopters when it becomes feasible. Currently, LEDs are between 10 and 100 times below the luminosity we would require to build a searchlight out of an array of LEDs. Beyond this, there is an issue called dispersion, which is related to how well confined the light remains within a column. In a traditional searchlight, there is a spark gap bulb that generates light from what is approximated as a point source for the light, with a parabolic mirror used to develop and contain the column of light. LED arrays require that the parabolic mirror be removed entirely, and instead a specialized lens is glued directly atop each LED. These specialized lenses are not yet able to produce a column of light that's well controlled over the thousands of feet at the intensity we require. If you are an engineering student and wish to implement the first LED-based searchlight, give us a call, and we'll provide a lot of technical expertise to your project (most of it for free!).