Custom Spell Icon

I made a custom icon for a spell but there is a problem. I have it so that you must first research an upgrade before the unit can use the spell. The problem is that when you click on the unit and the spell isnt researched yet, there is just a big green box where the spell should be, how do I fix this?

you have to import an icon that shows the the image you want disabled (a darker verison of it)
i think i am not exaclty sure how to fix it but i think that is the problem
make make sure everything has an icon in relation to the skills (even turn off area of the skill)
anyways i like the idea of the skill, what skill are you gonna try to make

You need to insert the "disabled" version of the button.

Lets say you named the button "hobo"

You would change the path to "ReplaceableTextures\CommandButtons\BTNHobo.blp"

And you would make a disabled version, and its path would be
"ReplaceableTextures\CommandButtonsDisabled\DISBTNHobo.blp"