The Style Settings feature in VCE involves two types of variables: campaign-level variables and block-level variables.
The Style Settings option is available as a tab in the Content Creation step where you can modify the template elements, while with the Block Style Settings available on block-level you can further fine-tune the appearance of your blocks. During all these, the original template will be untouched.
Campaign-level style settings
Style Settings are a way of applying campaign-level style changes to parts of the email, without affecting the original template settings. They are based on variables that you define in the template. You can set as many variables as you want, and then apply the changes in style for every campaign created using that template.
For more information on setting up these variables, see Setting up template variables.
Let's see this in action. In this example we have set up several variables in the campaign. This simple campaign has three, almost identical blocks, they only differ in their arrangement. We will modify the background color of the call-to-action (CTA) button within the template.
Now, change the background color of the CTA buttons:
As you can see, the backgrounds of all of the CTA buttons have changed.
You can also change the background image on a campaign level. You can insert an image from an external URL, or from the Media Database:
When using external URLs, make sure the images stay available through the entire lifetime of your campaigns.
For all campaign-level variables, the Reset icon is available to apply the default template settings of the given variable.

All the other campaign-level variables can be freely edited in the Style Settings pane, without affecting the original template.
Block-level style settings
With block-level style settings, we drill down into the depths of the email template and apply changes to the lowest level: the blocks. While doing this, not only the original template remains unchanged, but these settings do not alter the campaign-level settings, either.
Let's see how this works: we will have a different background color for all three CTA buttons of this email.
Hover your mouse over the block you wish to modify, and select Open Block Style Settings in the block toolbar.

Open the Block Style Settings pane for the block, and change the background color of the CTA button.
Now, if you go back to the Style Settings tab, you will find that neither the campaign-level values nor the original template values have changed.
For all block-level variables, the Reset icon is available to revert the values to the campaign settings, not to the default settings coming from the template.
The possibilities are virtually endless. You can have as many block-level variables as you wish, which allows you to create complex and diverse emails, without the need to create a separate block and its variables for each idea.