DETROIT – Hella is planning a slow ramp-up to introduce more personalized vehicle interior lighting for North American drivers by testing some options in European markets, where the Germany-based supplier says consumers have responded well to a variety of options.

As auto makers seek to court finicky U.S. drivers with everything from memorized seat positions to voice commands, interior lighting is the next frontier. Bulb lighting isn’t quite obsolete, but interest in light-emitting diodes is growing, Hella executives say during Tech Crawl, an annual supplier event here.

While most interior illumination is found on the instrument panel and center console, Hella and other suppliers have experimented with lighting door handles, cupholders, map pockets and steering wheels.

In Europe, Hella has been testing LED interior lighting across the color spectrum by building the technology into auto makers’ existing products. The supplier says men prefer an ice-blue color, while women like amber.

Such technology is less than five years away in North America, Hella executives say, pointing to recent successes with the Audi A8 and A6 interior lighting options, whichilluminate door panels, instrument clusters and center consoles.

“Light is psychological,” says Herbert Wambsganss, director of development for Hella. “Few subjects prefer white light.”

LED lighting is most popular in B-segment vehicles in Europe, he says, noting that by 2016, 12% of all vehicles in North and South America will have the technology.

Hella says exterior lighting is another growing trend. While drivers one day will be able to personalize which color headlamps and taillamps flash when clicking the key fob, lamps underneath door sills can provide added security.

Even personalizing lights in the trunk and above the windshield will come into play, and lights under arm rests and inside the glove compartment will see a return.

“All the lights that we had years and years ago are starting to come back,” says Dave Grasso, lead design engineer for Hella.

Auto makers are ready to embrace the technology because there is little cost difference between bulb lighting and LEDs. Hella says it is working with some OEMs, while declining to name them, on personalizing colors for increased brand recognition and ensuring there will be no color clashes with interior seating.

The only hurdle the company and other lighting suppliers see is marketing the technology to consumers. Few dealerships have ways of displaying LED lighting in bright showrooms, so Hella’s marketers are trying to persuade auto makers to better communicate with their dealers.

Hella also encourages OEMs to display interior-lighting techniques in product and sales manuals.

Hella says it’s working to reduce distracted driving by making sure interior colors and lighting levels are not too harsh. It also will not sync lighting with a car’s sound system or have flashing, multi-color lights, as are found in some youth-oriented car models.