Cannot set a different transparent colour than magenta

[greenwebsevilla]

Hi, thanks for your tools, I am new using it but I think it is not posible to change the transparent colour, am I right? I created the palette using this: Tools -> ZX Next image conversion -> Detect from uploaded image -> Download PAL the generated palette included the colour magenta, but when I load it in the editor, it takes it as transparent and the color is not showed.

I tried to import a BMP using my new palette (I unmarked the option "use magenta as transparent") but the magenta is always erased from the palette and from the sprites.

It would be very useful to redefine the tranparent colour.

Thanks in advance!