Show String Picture - System/image.png displays incorrect transparent color

[jetrotal]

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Name of the game:

Maniacs - custom life bar using Show StringPic Tutorial: https://www.rmteka.pl/maniacs-patch-nie-gryzie-10-prosty-hud-wersja-alternatywna/

Player platform:

Windows 64x

Attach files (as a .zip archive or link them)

https://www.rmteka.pl/wp-content/uploads/2023/04/prosty-HUD-przez-show-string-picture.zip

Describe the issue in detail and how to reproduce it:

That's a weird one. In this tutorial, the user created a HP bar using show string Picture and a custom System Graphic background(the images from the ./system/something.png).

In the image bellow there are 2 examples, one displays correctly the opacity of the image (RPG_RT), and another shows the player interpreting the color-index-0 as black instead of transparent:

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their hack is basically avoiding the use a system graphic like this:

and instead, using it like this: