I would say using a comma to combine the two sentences.
Answer:
Colored text and images.
Explanation:
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.
He tells Percy the story about the tree and a girl named Thalia. The story was that Thalia, Annabeth and other half bloods where exploring outside of the half blood camp. But then monsters came out of nowhere and started fighting them. They tried to fight the monsters but they weren’t strong enough. So Thalia protected them and risked her own life to save them. But thalia died and Zeus her father grew a tree in her honor, and the tree provided a barrier for the camp to keep them safe. :-)