If I remember right "the green" in reference was not the colour, but the shamrock - which was being used as a nationalist/anti-union symbol, similar to the uncrowned harp (as opposed to the crowned harp or crowned shamrock).

The Volunteers who adopted the shamrock as their emblem were a legal yoemanry force who adopted the customs of other units that used stylized flowers/plants/whatever as symbols - roses, leeks, etc., After the Act of Union, these symbols had a crown slapped on them and POOF! Symbols of loyal Irish.

"The green" in reference was not the colour, but the uncrowned shamrock - which was being used as a nationalist/anti-union symbol, similar to the uncrowned harp (as opposed to the crowned harp or crowned shamrock). I can, in addition, find no firm reference to any particular law or statute that would limit the "wearing of the green," per se, except as an act of sedition.

I suspect this is part of the myth that grew up, similar to bagpipes being "banned" in Scotland after Culloden.

As far as the army, etc., Royal Ulster Rifles wore a crowned harp as their cap badge, Connaught Rangers' cap badge was a crowned shamrock (WWI vintage). Their successor regiment, the Royal Irish Rangers also wore the crowned harp as a cap badge - No Idea what THEIR successor regiment (Royal Irish Regiment) wears - quit collecting badges before they were formed.

On a side note, the pipers of the Royal Irish Rangers had an immensely ugly uniform - Forest Green tunics with saffron kilts. Ethnicaly pleasing - but hard on the eyes.

Teribus' information on the "Green Jackets" is correct.

Pete