Issue with fillable text-box colours

So the problem (see picture):

I added fillable text boxes, so my clients can fill these area's themselve when they open the .pdf. As you can see on the right example, the boxes appear filled with a light grey colour. I think its very ugly, so i want the boxes to be transparant (just the colour of the boxes, not the text obviously). 

So the left example is what i want the file to look like. 

What i tried:

- Had contact with employes, but it looks like they didnt understand the issue.

- Whent to preverences -> forms -> uncheck ''border hover color for fields'' -> does work in acrobat, but doesnt change anything on the actual pdf, its just the previeuw in acrobat that changes. 

- Clicked on -> more -> unchecked ''highlight existing fields''. -> same problem the one above, only changes the previeuw in acrobat, but doesnt change anything in the actual .pdf. (when openen in browser or anywhere else outside of acrobat). 

Anyone has a solution for this? 

Examples: