[Bug]: Scripting Gradient rgb is misconfigured

[Alasdairbugs]

SuperTux Version

v0.6.3-1566-ge43838b1d

System Information

Win 11 64bit

Expected Behavior

g1 is the name of my gradient that I am changing colour. Using these scripts, I should expect the gradient to go from blue, to green, to purple.

g1.fade_color2(0, 139, 223, 0.1);
g1.fade_color2(0, 196, 22, 0.1);
g1.fade_color2(182, 1, 250, 0.1);

Actual Behavior

Instead it turns from blue, to the same shade of blue, then to white. I'm unsure as to what exactly is misconfigured. It is important also to mention that the alpha value is completely missing in the scripting reference

Steps To Reproduce Actual Behavior

reproduce with the scripts as above. Please use these rgb values and clipboard them to some tiles so you can see how they are supposed to be normally:

blue rgb(0,139,223)
green rgb(0,196,22)
purple rgb(182,1,250)

Additional Information

Might be related to #3148 but I'm unsure.

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[Alasdairbugs]

Furthermore, dark brown rgb(26,21,0) is yellow, for some reason. red, rgb(253,0,40) also looks a bit pinkish.