what is the "code" for a transparent "color"

This is not really specific to aircraft repainting.... but this is the best place that I could figure to ask this question.......... since it is about repainting.
I need to have a graphic element "disappear" on an existing graphic that I cannot actually alter directly (the element is uneditable). I CAN change the color of the element based on a custom color selector that I THINK is a stock MS active control for software like Visual Basic.... I've seen this control in many apps.
The pop-up gives me the following that I can type numbers into:
Hue
Saturation
Luminosity
Red
Gereen
Blue
Is there a "code" combination that would make the graphic element appear totally transparent in order to let the background color thru it as if it was not there?
Appreciate any help anyone might give me on this one.
best,
.......................john
I need to have a graphic element "disappear" on an existing graphic that I cannot actually alter directly (the element is uneditable). I CAN change the color of the element based on a custom color selector that I THINK is a stock MS active control for software like Visual Basic.... I've seen this control in many apps.
The pop-up gives me the following that I can type numbers into:
Hue
Saturation
Luminosity
Red
Gereen
Blue
Is there a "code" combination that would make the graphic element appear totally transparent in order to let the background color thru it as if it was not there?
Appreciate any help anyone might give me on this one.
best,
.......................john