When I need to retrieve the background-color of a WebElement, I typically use the following code:
string color = IWebElement.GetCssValue("background-color");
Selenium often returns something like this for the color value:
color = "rgba(153, 255, 255, 1)"
Upon inspecting the element using a tool such as firebug, I see #99FFFF without any transparency. The element appears to be fully opaque in both configuration and display.
This raises the question of where the alpha value "1" is derived from. My understanding suggests it should be "255" instead.