it just not work for glass and glass pane and also custom glasses/panes from another mods like chipped, chisel or patterned glass mod not working.

You can color white stained glass

click on any wool, glass block, glass pane, concrete, slime blocks and bricks, including stairs and slabs

But in mod description glass block and glass pane is mentioned. please remove it and add the stained glass instead
other than this there is nothing left and you can close this issue