This looks kind of like line art to me. The reason I say that is because they have pretty solid colors, and sparse shading. Some dithering going on, which might be useful at this resolution, but you're going to have to invest in some serious texturing to garner visual interest. Also, you should post a character sprite for scale. For instance, some objects look like they are taller than they should be, like the counter or the front facing bed.
About the colors; there are a few things you can do. Study the color/pallet of a game/mockup that you think works well, and try to understand why it works, then emulate it. Also color stealing, or using other people's pallets is perfectly ok, even within the strict moral ethic code of pixel art. It's something that will help you understand color more. Also look into hue shifting: instead of using the same spectrum of a single color, shift it into cooler shades for the shadowy parts, like purple, blue, green, and warmer colors for the brighter shades, like red, yellow, orange. If you think it looks bland, then change it up. Knowing about color theory in general also helps make better color choices.
