Her first lightsaber was created by herself while she was taught under her twin brother, Luke Skywalker. During the Thrawn campaign in 9 ABY, it was used by Mara Jade to kill both Luuke Skywalker and Joruus C'baoth. This lightsaber had a green blade.
During Operation Shadow Hand in 10 ABY, Leia briefly used a 10,000 year old lightsaber that she got from an old Jedi Knight named Vima-Da-Boda. On Byss, Leia used it to slice the hand off of an Imperial Sentinel before Darth Sidious made it explode.
The color briefly became pale blue when she dueled and killed the fallen Hutt Jedi Beldorion with it on Nam Chorios in 13 ABY.
In 18 ABY, Luke gifted her a second lightsaber that had a ruby-red blade that he built from scratch. The lightsaber is described as smaller than her previous one.
While training under Saba Sebatyne, Leia's lightsabers were taken by her new Jedi Master, who told her that they did not reflect her skills anymore, and that it was time that she build a new lightsaber, one fit for a fully-fledged Jedi Knight. Leia had built a blue-bladed lightsaber that she used throughout the Swarm War and thereafter.
While the text of Dark Force Rising specifically calls Leia's first lightsaber "green-white" in Chapter 24, as the does the text of The Last Command in Chapter 27, and it appears as green in the fifth issue of the comic adaptation of Dark Force Rising and on the cover of The Last Command, it was depicted as blue in the sixth issue of the comic adaptation of The Last Command and is described as blue in Planet of Twilight.
When asked about what type of lightsaber she would like during an appearance on The Late Show with Stephen Colbert when promoting her new book The Princess Diarist, Carrie Fisher said she liked the color purple.