When I put my cursor over the color that I typed, the workspace doesn't show what color it is going to be.

Hey Qiao, can you be a little more descriptive of what you're trying to do here? I'll take a stab at it anyway...

The workspace, like other code editors generally don't tell you what color something is going to be when you put in a hexidecimal value or rgb value. You can infer what the color is if you have studied how the hexidecimal valules and the red green blue spectrum work, but the editor itself will generally be void of notifying you what color it will be. This is due to the editor's nature. This is also why you have to refresh the browser to see the result because the browser is what is actually interpreting the code and drawing it to the screen. If you want to be explicit, you can say

.classname{ 
/*Explicit White*/
color:white;
}

I created a little CSS Test workspace to show how colors can work in different classes utilizing the hex,rgb, and color name. Here's a nice little resource to help you gain more understanding around hexidecimal and rgb color values. (It'll also help you get the code you want for the color you want)

The CSS file "styles.css" is your main focus in the workspace. I've added comments so that when I'm reading the code I know what the colors of each value so I don't have to refresh the page everytime to check it out.

.color1{
  /*Orange-ish*/
 color:#FF5500;
}
.color2{
  /*Red + blue = ...? */
 color:rgb(255,0,255); 
}
.color3{
  /*If I had to guess, it's going to be blue*/
  color: blue;
}

How are you formatting the colors? As hex values, rgb, or typing the name?

Also, maybe it's a browser-compatibility thing...are you using Chrome?

Strange! Not really sure what would cause that then. But I wouldn't worry about it too much, even though it's a minor hassle - when I started building projects in text editors instead of workspaces, I had to get used to a lack of color preview anyways.

Coolers is another useful site to use when picking and referring back to color palettes for sites. I'll bookmark a particular palette and just refer back to it while working on a project.