There are a number of characteristics that make up a color. "Hue" refers to the color, itself; where it falls in the color spectrum. Color is reproduced by combining primary colors, like red, green, and blue, to create other hues.
"Saturation" refers to the purity of the color. You can start with any hue and add white to make it lighter or black to make it darker. Saturation doesn't have a color, it's a measure of intensity or purity of the color.
Pale refers to any color where the saturation has been reduced by adding white to make it lighter. It has no color, itself. You get clues to the color from the context. A pale sky will have a sky-colored hue (bluish), but be washed out or less saturated that its normal color. Pale skin will have a skin-colored hue but be washed out or less saturated than its normal color.
Pale eyes would be eyes that have a lighter, less intense color. They could be any hue found in eyes, but because of the way eye color is created, colors other than brown tend to be lighter and less intense. So if you had to guess what color eyes were that were described only as pale, it would more likely be something other than brown.