Transparent colors?

[RSpeed tycoonfreak]

I'm drawing new modern stations for ttd/ottd and I'm running on a problem:
Offcourse in modern stations you're having a lot of glass buildings and i want to know how do I make glass transparent?
Has it to do with the colors, or is it something with the coding process maybe?

[XeryusTC]

When coding newstations you can define a sprite as transparent. This makes every color (except from color 1 with the proper bits set in your action 1 block IIRC) look like glass. Look at the documentation, especially the part about the sprite IDs and offsets etc. IIRC for glass you want your sprite ID to be 0x03883342D+X but I'm not sure about that.

[athanasios]

and:
If you decode the original grfs you will see that the stations have an extra sprite for transparency (yellow color: but as already stated, except color 1, any color can be used).