Yes you can!!
You do it with CSS.
You give the blockquote element a class attribute in your (X)HTML or post, and define the class in the style.css file of your theme. You can also use inline CSS but then you have to write the CSS in each blockquote which is not recommended because, if you ever want to change the style, you have to go back and change each blockquote in every post individually.
I recommend you do it somewhat like this
The (X)HTML you write like this:
<blockquote class="green">content</blockquote>
and
<blockquote class="red">content</blockquote>
In your style.css file you ad:
.green { color: green; }
.red { color: red; }
You can also define the color in hexadecimal numbers ( #008000 for green and #ff0000 for red ) or even in RGB, although that’s not commonly used.
Remember, when writing CSS, that a class name always starts with a period followed by a letter and can’t contain any spaces ( .red ) you can’t start with a number after the period.
good: .red { background-color: red; }
wrong: .1st color { background-color: red; }
(number in wrong place and has a space)
good: .color_1{ background-color: red; }
You don’t have to limit yourself to just a color. You can give the blockquote (or any other element) a background image: .red { background-image: url(/red.jpg); }
, a border: .red { border: 1px solid #008000; }
, different background color: .red { background-color: #FFFF00; }
or a combination of them.
On my own website, VanBerghem.Com, I styled my blockquotes as followed:
blockquote {
border: 1px solid #FF6600;
background-color: #CCCCCC;
background-image: url(/imagepath/quote.gif);
background-repeat: no-repeat;
padding: 20px 15px 10px 30px;
margin: 10px auto 0px;
}
You can see it in action here
I hope this answered your question.