Funny, last week I was looking for information on this. So many of us have those 70's houses. I did "color-meshing" and it came out awesome and had a 26x16 room done in two days. I did a small space whitewash and it just looked strange.
I lightly sanded the walls, primed with Kihls and used earth tone paints (Mushroom Taupe and Dover grey). The color meshing is soo easy. You just take something like a large sponge and dip you brush in the paint and run across the sponge. Do the same with the other color(s) so you have multiple colors on the sponge. Then slop some paint on the wall (both colors in different spots) then just tap the sponge on the wall and the colors blend slightly. You may want to add a bit of water to the paint to thin it (1/2 cup to 1 gallon paint). It only took me a gallon of each color to do the whole room