how to edit a specific color in a theme

[cabraham03]

Hi, I made a theme based on available theme, PlasticCodeWrap, I made changes in color, I just want to change one thing, the window used to open a files in RStudio, the actual color is dark, and I want in light color, I just want to know the name of the variable in the code of the tmTheme file, or in the online editor, which element do I have to change ?, or how to identify the color for the import files window.
Thanks