Welcome to the wonderful world of quilting! Biggest reminder - do not try for perfection, go easy on yourself. With each project you will learn and you will get better. I have been quilting for over 40 years (sewing for over 60) and I still learn things with each project! With this top, your colors are fine. I might suggest switching the 2 on the left, move the dark grey/blue to the lower left corner and the light grey/pink to the upper left corner. Then leave the room and re-enter a few times. How does it look to you? This is why we audition fabrics/blocks/borders. Does it look better to you than the first one? If not, move it back - YOU ARE THE BOSS! Other than the 1/4" seam rules, there really are no rules and you get to decide on what is right or wrong and you'll learn what works and what doesn't. HAVE FUN!!!!!!!