It is interesting to read your frustrations! I cannot tell you how many times I ripped out my earlier pieces! (and often the current ones) Just keep on trying! It is better to make your seams more generous so they don't come apart later! (Ask me how I know.)
The color thing always amazes me also when I try to MAKE it come out right. Then I go out and see flower gardens and LOVE how all the colors go together even when they don't at first. Think back to the 70s and the colors we wore then, and the colors we wear now! And who would have put pink and brown together a few years ago? Don't Worry, Be Happy! Just go with what works for you. There is a red film to use to look through to see the values of the fabrics which is mush more telling than the color! Interesting! :?