Most common mistakes:
1. Picking the paint color to early. It's perfectly fine to go into a design project with a general color idea: I want a red dining room; I want a yellow kitchen; etc. However, you need to leave off picking the exact shade until you've selected whatever is the most difficult to co-ordinate part of the project. Depending on the room, that can be drapery or upholstery fabric, tiles, flooring, countertops, rugs, art, etc. Here's why that hard to find item should be picked first, if at all possible: Suppose you want a yellow kitchen for your 40s bungalow. Additionally, you want to do a backsplash with a yellow and white checkerboard pattern, as well as some vintage inspired yellow floral cafe curtains (yes, I know it all sounds too twee to endure, but I'm just using it as an example...it's not a real room). Any tile store you go to is only going to have a very limited selection of yellow tiles...maybe only one that's appropriate for your application. You'll have more luck finding a floral print with yellow, but even with a large fabric selection, it will be hard to find the right combination of print you like, yellow color that coordinates, fabric type you want, and price that is affordable. The chances of either of those things matching a preselected yellow paint is very slim. This would be an even greater challange when working with a color choice that isn't particularly fashionable, such as cobalt blue or forest green. However, if you pick your yellow tiles first, it's an easy thing to match a yellow paint to them, even if you have to resort to computer matching. So in short, there are thousands of different shades of paint, inluding custom blending and computer matching. There is, however, a limited supply of home furnishings. I used to see it all the time at the furniture store: clients who had just spent thousands of dollars to paint their open floor plan living space only to realize that in the entire store's selection of hundreds of fabric options, they were able to find only a handful of fabrics that co-ordinated with their neutral, supposedly goes with anything paint.
2. Not testing paint or not testing it correctly. There is no way to pick a color from a 2 inch square. Those things lie like a cheating boyfriend. The paint turns out more intense, or darker, or lighter, or bolder, or duller, or greyer, etc. than the chip itself. If you are experienced with picking color in general and the paint color itself, you can form an educated guess about how that 2 inch square will look covering acres of wall, but honestly, it's at best still a guess. The only way to know what a color will really look like is to test it, on several areas and in different lights. And the way to test properly is to buy a quart and paint it on a piece of poster board on which you have left a white border. If you paint it directly onto the wall, the wall color will affect what you see in two ways- by giving an undertone to the paint and by a direct comparison. How a color looks is influenced by other colors next to it. So the only way to judge the new color is by surrounding it with white so no other color directly influences. Skip this step at your own risk, especially in the case of a major paint job.
3. Using a color (without testing) because it looked great at someone else's house. Seeing a paint color at another person's house can actually be a great way to find color inspiration. However, before you use it at your own home, you need to do more analysis. Ask yourselves these kinds of questions:
1. Will I be using the color in a similiar proportion? i.e. That bold pumpkin that brings a small powder room to life could easily be overpowering in a large full guest bath.
2. How similiar are our homes? Are both tradtional with similiar mouldings (large white or cream mouldings have a major impact in calming intense, dramatic, or dark walls)? Are our floor coverings similiar? Do we have similiar furniture? For example, a black dining room in a contempoary house with honed travertine floors, a mirrored table, cream leather chairs, and several large, primarily white abstracts may not feel dark at all. However, the effect will be vastly different if you transfer those ebony walls into a dining room with dark wood floors, a jewel toned Persian rug, and mahogany casegoods.
3. Do the homes have similiar light exposure? Homes with a lot of natural light can handle many more types of color than one with much less light. What looks bright and cheerful when washed with sunlight can quickly become strident, harsh, and garish in a dim space lit with artifical lighting.
4. Forgetting how the color interacts with other rooms. Most rooms do not stand alone. In an open concept floor plan, how colors intersect is a more difficult and problematic issue, but even in traditional spaces, you need to think about how the color of adjoining rooms look together. In addition to the wall colors, you also need to think about how the new color will look with flooring and furnishings in other rooms. They need not match, but should complement each other.
5. Following Trends. Fashions come an go in paint colors, just as in clothes and makeup. Even neutrals change: when I first started in design in the 1990's, most of the beiges we worked with had pink undertones; now, they go green. But when you're picking color for your own home, Number 1: think about what you personally like. No color is bad. If you've always loved hunter green and navy, but have shied away from using them because they're too 80s---ignore the haters and go for it. With the right furnishings and details, even "out" colors can look fresh, modern, and beautiful. Number 2: keep in mind what fixed items you have to work with. It's certainly better to go with a "dated," but beautiful pink toned taupe that flatters your cabinets that can't be replaced, than to go with the latest yellow toned beige that clashes.
Image from my 50s year blog here.