Thanks for the advice. Did try
irFanView but when I opend the arrows they were blurry.
The only tools where I could open the .png files and see the transparency were
Photoshop and
Paintshop Pro.
In Photoshop I didn´t find out how to modify the colors.
In Paintshop Pro I could modify the colors of the pixels and the tried save as ... and optimize png but I did never get transparency although i checked singel layer transparency or alpha channel transparency. I did read the instructions in
http://www.libpng.org/pub/png/book/chap ... ch04.div.5 but didn´t get it working.
Which options should I use in Photoshop Pro "optimize png" to get transparency.
It worked when opening a file in Photoshop Pro, the editing and just press save.