transparent background with GUI.DrawTexture

Hi !

Sorry for my bad english, it is not my native language...

I want to display a texture with GUI.DrawTexture. T$$anonymous$$s texture has transparency, but when I display it, the background (set to transparent thanks to PhotoFiltre) is displayed with w$$anonymous$$te color (color without transparency). I thought I found the solution here: other topic, but the "GUI" texture type is not suggested in my texture inspector: there only is "Editor GUI and Legacy GUI". So I selected t$$anonymous$$s one, with "trueColor" format as in the other topic, but it didn't work. In addition, it is written in the bottom of the inspector on the preview "RGB 24 bits". The only way I found to get "ARGB 32bits" is selecting "Advanced" texture type, and selecting "Alpha from grayscale". But of course, the alpha is according to Grayscale, and not to the source alpha channel...

Another way to solve t$$anonymous$$s problem is to set a color as transparent, so that the background (color = (255,255,255)), is transparent, without caring about the source transparency. But I don't know how to do that...

Please help me ! Thx.