For the text color. Highlight the text you want to change the color of, then select the color from the 'change color' drop down selction. For images, you need to upload the image somewhere then copy the URL of the image and past it. Now highlight the URL in your post and click the image button.
I'll add a $ to the code so you can see what it would look like.
[color=$red]Yadda yadda yadda[/color]
[img$]http://blackwidows.co/wp-content/uploads/2016/06/sheep.jpg[/img]
Taking out the $ would give you the following result.
Yadda yadda yadda