In looking at the picture and what you have, it appears to me that one 'arm' of each star is inserted into the row of the next, allowing for the curve in the rows. My impression is that without hue change, you may not have the inward spiral effect, also. I suspect this may be one of those patterns where the instructions are less helpful than the picture. Good Luck!!
The colors are correct. They are pieced in opposite colors and are placed on opposite sides of the circle. If you look at the blue and yellow sections you can see the effect.