Hotels, they are a'changin', as hoteliers develop properties that cater to younger, tech-savvy generations.

New and older brands are making moves to do away with the beige, interact via apps, double as co-working and social spaces, and score shareable selfie love along the way.

But don't call them "millennial hotels." Scott Greenberg, the owner and founder of Hotel EMC2, a smart new Chicago hotel with an art-and-science theme in Marriott's Autograph Collection, says he knows that if he develops a hotel that his three millennial children will love, older generations will follow.

While amenities such as free Wi-Fi and stellar bar programs are practically a given now in hotels looking to woo younger audiences, here are some other trends to look for on your next getaway.

Aspiring to be Instagram-worthy: Many hotel developers now know that a piece of cool art doesn't just have the potential to appeal to a guest, but also has the potential to appeal to all who follow that guest on social media.

"From a design and art standpoint, we've got a lot of very bold art that creates backdrops for people to take selfies and share online," says Rose Anderson of Radisson Red, which has locations in Minneapolis and Brussels, as well as Cape Town, South Africa, and Campinas, Brazil.

The colorful and creative design of Hotel EMC2 banishes bland and is irresistibly shareable. The hotel commits to its art-and-science theme, and is punctuated with antique books, vintage microscopes and nods to great scientific and artistic minds. In the rooms, dramatic and photogenic showers — inspired by laboratories of the 1920s — are a centerpiece, and are translucent on three sides, while mirrors have an infinity effect and beg for selfies.

Connecting guests with local favorites: At Hyatt Centric, staffers are encouraged to share their favorite local spots with guests. "It's no longer just the job of the concierge to give you recommendations," says Sandra Cordova Micek, Hyatt's senior vice president of global brands. "Our colleagues are constantly being asked what their hidden gems are and what they would recommend."

In addition, the hotel places original local guides in rooms. It also highlights local art and food; some properties offer area tours. At Chicago's Magnificent Mile location, for example, guests are invited on neighborhood and brewery tours, and a hotel manager leads guests on morning runs.

Residence Inn partnered with Under Armour to offer its extended-stay guests at least one running map, via the app MapMyFitness.

Residence Inn properties host events three nights a week, dubbed the Residence Inn Mix, which include visits by local food trucks; gatherings with appetizers, desserts and premium beer; barbecues; and tasting and educational events that bring in chefs from local restaurants. Those offerings were inspired by research that found that millennials traveling for business were looking for fun, social events that connected them to the city where they were staying.

Revamping room service — and menus: Some hotels are moving away from stodgy room service trays with silver domes. Hyatt Centric tailors its room service to on-the-go guests looking to explore the city, Micek says.

"It's actually having your food delivered in environmentally friendly packaging that comes in a paper bag that you can take with you," she says.

At Radisson Red, guests can order grab-and-go food from on-site restaurant OuiBar + Ktchn using the Red app, then take it back to their room or out on the town.

At Hotel EMC2, multiple vegan options are available.

Changing the form and function of lobbies: In these days of laptops and mobile offices, people like to work alone — together. Hotel lobbies are accommodating that, offering lots of work spaces — as well as plugs and free Wi-Fi — with easy access to snacks, caffeine and cocktails. At the Hyatt Centric on Magnificent Mile, the lobby is the kind of place where you could spend days on end. It's filled with playful local art, and includes a library and dozens of comfortable chairs and tables, all of which spill into the bar, which spills into the restaurant, with no walls separating the spaces.

Gone is the traditional lobby at Radisson Red: The brand banished the front desk. At the Minneapolis location, guests can check in using the app on their phone, then use the phone as the key to get into their room.

Adopting a high-tech approach: That Radisson Red app is also your key to communication at the hotel. It's possible to spend a night, or week, there and not physically talk to anyone but still manage to order food at the on-site restaurant, call a cab, check in, check out, request more towels and even chat with other guests.

At Residence Inn, Radisson Red, Hyatt Centric and Hotel EMC2, guests can stream Netflix onto the television. Hotel EMC2 guests can also control the lighting and thermostat using the TV remote control, and each room has an Amazon Echo unit that streams music, reads the weather report, looks up info on the web or does other tasks via voice command.

At Hotel EMC2, two robots, Leo and Cleo, bleep and bloop up the elevator and down the hallway to deliver bottles of water, toothbrushes and extra linens to rooms, upon request.

Social consciousness: At Radisson Red, you won't find any paper — except toilet paper — in the rooms.

When Greenberg came up with the Hotel EMC2 theme, he wanted to inspire dialogue about art and science. The hotel provides financial support from direct bookings to Project Syncere, which helps pave a path for students in underserved communities to pursue science, technology, engineering and math careers.

"Millennials want to feel like there's something of value, that somebody cares about something and that their money is going to serve the greater good," Greenberg says.