Here is some hit or miss inspiration for you as you work on the chair pad. The vintage rug above is at least 50% neutral colors. Notice that the artist does not make an attempt at making the color homogenized, but is not afraid to vary colors across the canvas. This is especially true in the case of the black wool.
The hit or miss background in the piece above has mostly medium and light values in it. This helps the darker motif at the bottom show up without the background looking like it is attached or growing out of it.
In the two examples above there are hit or miss sections. Each section stands as a distinct whole as compared to the other. That is because the values are selective. The darker sections of hit or miss have medium to dark values, whereas the lighter sections of hit or miss are hooked with medium to light values.
The vintage rug above uses only a few wools that are repeated randomly. Notice how many wools are neutral in color.
Keep hooking ~ Karen