The Hwo character evolved over the years, really a different character at different times. Originally, the character was not even a Force user, but was a spy for the New Republic Special Forces that was anti-Force users and kind of monitored/chased them down. That was shortlived back around late 2000ish, and I rewrote the character as a Jedi probably in 2001 or so to replace my deceased character Ice Fox.
For the longest time, Hwo used a green lightsaber because that was my personal favorite color. I started RPing in 2000 at age 12, and Qui Gon was my favorite character. There was never a question -- green > blue. I saw no reason why my character should have a special color, i.e. white, purple, orange, etc. There was never anything fancy about the lightsaber, and I was never descriptive of the hilt or anything. For a while, I wrote it as having a slightly longer blade because as I got older, I based the character's physical characteristics off of my own, and I am 6'4". Because my RPing became sporadic after around 2004 or so (basically when I got a license at 16), I wrote Hwo as more of a wandering Jedi character, and the green blade seemed to fit the nomadic lifestyle in my opinion.
As time went on, I wrote Hwo into more of the fast-paced battles at TGC. While I maintained that his primary weapon was his green single-bladed lightsaber, he would sometimes "borrow" a blue double-bladed lightsaber from the Jedi armory for the battles. I never liked the idea of a Jedi having a double-bladed lightsaber as a primary weapon, but it was fun to switch it up for brief battles.
While I have not RPed in years, I think of Hwo today as having strayed a bit from the traditional Jedi path. I think of him as having abandoned the robes for more civilian garb, similar to the Kyle Katarn avatar I use. I also think of him having moved from the green blade to a blue blade to reflect that. A lot of that is a reflection of my own personal changes over the years, and I have always based parts of this character on myself, as if he's the extension of me in this universe. My inability to separate myself from this character really created a weakspot in my writing and character development that I recognized but struggled to resolve.