Unselect area after color tresholding selection

Hi all,
I’m using ImgeJ > adjustement > color treshold to select areas in histology images for quantification.

I’d like to remove some areas at the stage of selection or before that because it’s taking some areas that should not be selected, i’v tried the ‘lasso’ like tool > freehand selection and then pressed control X , but after that I see that it deseleted all .

If i use the tool before the selection process ( press control-x before that) it still counts that area even if i see a white spot…

Using Fiji last version.

Thank you giving me direction how to remove areas manually after color tresholding method…