Traditionally speaking, summer isn't really the time to go heavy on your eye makeup (save for those special occasions you've got planned for the evening). Light, shimmery shadows work best, but there are variations on this theme that will serve your changing moods throughout the season.
For tried and true colors, stick to neutrals such as white, cream, gray, beige and brown. These are colors that are universally flattering and are bound to be a good choice for any lady – as well as be reliably work-appropriate.
If you're bored of these colors, cheer yourself up with loud, fluorescent shades that still pack a lightweight texture. If you're going to amp up the color, it's best to apply a solid stripe on your upper lids paired with minimal makeup on the rest of your face.
That being said, you don't even have to stick to eyeshadow if you feel like mixing it up. Using a cream highlighter on your lids (or even a blush) is one way to get a subtle sheen – as is adding a touch of balm for a glossy lid effect.