Colored text draws attention towards the text, and images can help to support the content by giving the viewer a visual example/explanation in addition to the text.
Animation may distract viewers from the actual content of the slide if overused and will be unhelpful for anything other than making the transition from one slide to the other more appealing to the eye. Dark backgrounds can often make reading the text difficult, unless the text color is very light. It can also make images look worse unless they are also very light.
