You can add a layer mask to any type of layer or even to a multiple layers gathered in a group. To mask layer in Photoshop you simply have to be on that layer and press the Add Layer Mask button found on the layers tab. As you can see it adds a white layer mask meaning that the entire image is visible.
Accent Wall, Color, Color Consulting, Decorating, long narrow rooms, Paint, painted accent walls, Painting, what is the best wall for an accent wall. I think there are definite times when accent walls are great. I have used a darker wall at the end of a long, narrow room too with wonderful results.
Try a paint color in the room to make sure you like it and that it works with the space. Live with it at various times of the day as a painted wall will appear different in the morning, afternoon and at night. If you don't like it, paint over it. Color is a great punctuation and doesn't have to be overbearing.