Hi. I have your same coloring, and, with blue-gray eyes, often thought blue shadow, navy eyeliner or black, and black mascara were the norm for me and I did so in my teens - even going to that horrible fake looking turquoise shadow loaded onto my lids. Ugh!
However,
I read in a beauty book years ago that a sage green (not kelly or bright neon green) or soft grey-green color was best for my blueish eyes. Supposedly, the greens (and also brown-taupe-greygreen) colors were to enhance and bring out the opposing color of my eyes. Oddly enough, this color - sage green on the lid with a deeper greyish brown color in the crease blended into the green and then fading into a soft light cream color for the browbone above the eye, made my blueish eyes look all the more blue - particularly if I'd wear something in navy or another blue like teal that's good for me. We are all different, and the sage green on your eyes may not look all that great as on mine - mainly, most likely, because of our skin colors - some "fair skin" is more pink than others. I tend to look best with a cool color to balance my rather ruddy but very fair complexion (wear a high-SPF sunscreen ALL the time!). You may need a warmer shade. The shade of blonde your hair tends to be will also guide you to the right colors. More golden blondes seem to look best with the warmer shades of brown-tan-cream with just a toucj of a color like one of the greens or even teal-blues on the lid. My very pale (highlighted) blonde hair with little or no golden tone tends to look best with the cooler shades of sage, deep taupe or even a cool grey on the lid with a deep, grey-brown in the crease. The crease shadow is important, as it gives your face more definition and brings out your pretty eyes!
Have fun - love your cute "id name" of Peppersparks!