Houseplants can lift the mood of a room as well as adding decorative interest. If the mood you're aiming for is on the dark side, however, you might want to look for dark houseplants. They can really stand out in a room, especially when they're positioned against lighter-coloured walls.
The two smaller plants in my photos are Peperomia Caperata varieties: Rosso and Luna Red. Peperomia Caperata are compact plants which have deeply-ridged leaves. They don't really flower; they produce long upright spikes that look a bit like rats' tails, giving the plant an alien appearance. The dramatic Rosso variety has narrow, dark green leaves with a bright red underside. The Luna Red variety has dark purplish-red, heart-shaped leaves.
The larger plant in my photos is a Zamioculcas Zamiifolia (often abbreviated to 'ZZ plant') of the Raven variety. Its leaves and fleshy, thick stems have a waxy coating which can make it look shiny and a bit artificial. Raven is a fairly recent variety of ZZ plant, introduced in 2017. New growth is green - as shown in one of the images below - then its foliage turns darker and blackens as it matures. It's a slow grower, but given time can reach a massive 30 inches (76 centimeters) tall and wide.
The good news is that these plants are all easy to care for. In fact, the greatest risk to them is under-watering rather than over-watering. Apart from occasional repotting, they should only need infrequent watering, and bright indirect light. They can probably cope with low or artificial light conditions too, from what I've read. These are simply more interesting varieties of plants which have been successfully grown indoors for ages, in homes and offices, so they will hopefully survive around me.
I purchased both Peperomia Caperata plants from my local Homebase store. I got the ZZ plant at a discounted price from gardeningexpress.co.uk. I'm happy with it, but it took a very long time to arrive and the company has mixed online reviews regarding their customer service. At the time of writing this article you can also buy Raven ZZ plants from www.crocus.co.uk, which is a company with better reviews, and one I've had good experiences with.