How to color specific word in a container using CSS

Question

Suppose I have a container:

 
 This is a red apple 

How to color a word \"red\" with red color? Some

Answer 1

Use for this.

 This is a red apple 

CSS:

.red {
color: red;
}

Edit
It isn't possible without any additional Javascript or HTML. According to the CSS3 specification there is no such selector (There were thoughts about a :contains() selector for CSS3). Also see this and this Question.