From televisions in every room to smartphone room keys, the hotel industry has evolved to stay at least on pace with travelers, if not a step or two ahead. Now, challenged by the home-sharing economy — Airbnb alone reported over $1 billion in revenue in the third quarter of 2018, its highest to date — new hotels are toying with everything from pricing to privacy.

Airbnb, said Chekitan S. Dev, a professor in the School of Hotel Administration at Cornell University, “shook legacy brands out of their slumber and forced them to consider innovating their value propositions, and it encouraged entrants to experiment with novel and bold innovations.”

Today, he added, new hotel brands are routinely asking a series of “what if” questions: “What if customers could check in anytime they like? What if the room was customized to the needs of the guest? What if the room could be rented in parts or in combination with others? What if the guest determined the value of the room? What if there was a seamless experience between the hotel and the local community?”

The following three new hotels embody some of those experiments.

Beyond providing the convenience of having someone else make your bed and launder your towels, can a hotel room improve your mood? That’s the question posed to guests of the new Angad Arts Hotel in St. Louis.

The 146-room hotel, which opened in November, offers four color schemes designed to support emotions. Rooms come in yellow, said to be associated with happiness, green for rejuvenation, blue for tranquillity and red for passion (doubles from $185).

“While exploring ideas, we came across a quote by Pablo Picasso, ‘Colors, like features, follow the changes of the emotions,’” David Miskit, the executive managing director of Angad, wrote in an email. He added that the company used no particular source for translating emotions into color, but that “these were the most common interpretations.”

Rooms come with corresponding accessories, including a tabletop Zen garden with a mini rake in the blue rooms, a lamp set with Himalayan salt crystals in the green rooms, a smiley whoopee cushion in the yellow rooms and a scented candle in the red rooms.

In December, I booked a yellow room to test the effect, reasoning that anyone staying solo on a business trip could use a boost of happiness. My room glowed with warmth, from the yellow rubber duck in the bathroom to the overhead ductwork, also painted yellow. The morning sunlight streaming in only heightened the effect, making it just too impossibly bright and, yes, cheerful, to sleep past 8 a.m.

So far, blue has been the most popular choice among guests, said Mr. Miskit. “It’s safe.”

The new SCP Hotels stands for “soul, community, planet,” with the aim to operate sustainably and nurture connections between guests. Its first location, which opened in June in Colorado Springs, Colo., introduced a key component of its intended transparency with what it calls “fair trade pricing.” It allows guests to name their rate when checking out, meaning they can lower the suggested price if they feel the value doesn’t align.