How can I change the color or the transparency of the popup's overlay? I want to have another color and alpha 1.
['https://Stackoverflow.com/questions/4329478', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/69654/']
<http://mprami.wordpress.com/2008/04/22/alert_popup_modal_transparancy_color_blur_changes/>

In flex ‘’ tag has mainly four attributes related to modal properties of pop-ups.

* modalTransparency
* modalTransparencyBlur
* modalTransparencyColor
* modalTransparencyDuration

In spark it looks like these were renamed slightly:

* modal-transparency
* modal-transparency-color
* modal-transparency-duration
* modal-transparency-blur (guessing on this one)
To extend on artjumble's answer, if you're using a css file, you can also declare it like that in the css file: 

```
global {
    modalTransparencyBlur: 0;
    modalTransparency: 0.3;
    modalTransparencyColor: black;
    modalTransparencyDuration: 500;
}

```