vBulletin LTS

Step 1.
Copy the following into the additional CSS definitions (Admin CP > Styles & Templates > Style Manager > All Style Options>Additional CSS definitions) and paste it into the lower box.
CSS Code:
.spoiler
{
	background: Black;
	color: Black;
	border-style: dashed;
	border-color: White;
}
Step 2.
Now click save and go to the page to add a new BB Code (Admin CP> Custom BB Codes > Add New BB Code)
Enter the following (Exactly as shown!):
Title: Spoiler
Tag: spoiler
Replacement:
<center><font color="red">Spoiler Below</font></center> <div class="spoiler">{param}</div>
Example: [spoiler]test[/spoiler]
Description: Hides text
Use {option}: No
Button Image: Leave empty
Click save and go try it out!
FAQ:
Q:I want to change the color that the spoiler tag uses! How?
A: If you know CSS it is all controlled in the CSS definitions. If you do not know CSS let me know in the thread at vb.org and I'll see if I can help you.
Q: Why doesn't the example work in the admin cp?
A: I'm not sure, but it will still work in posts.