Here's some information pertaining to Sesshomaru -*test*-('")ing out his reforged Tetsusaiga (his Deadly Lethal Poison Fang):
Later, when 3 days have passed, Toutousai (who had no choice but to reforge the shattered Tetsusaiga from one of Sesshomaru’s fangs due to Sesshomaru’s harsh attitude and his threats) was done reforging Tetsusaiga and appears to Sesshomaru at his training area and hands Sesshomaru his reforged Tetsusaiga and says to Sesshomaru that Tetsusaiga has reached a whole new level of power now that it has been reforged from one of his fangs and then speaks to Sessshomaru saying that he should now -*test*-('") it out and see just how powerful it is. Hearing this, Sesshomaru takes his reforged Tetsusaiga from Toutousai and notices that the barrier is gone and becomes very proud that his expectation has been proven correct.
But after Sesshomaru has taken his reforged Tetsusaiga from Toutousai, there are a numerous herds of demons making their way towards Sesshomaru and Sesshomaru slowly walks straight ahead with his reforged Tetsusaiga in his hand and stands still.
Once Sesshomaru has stood still, there is a close-up of him who is now thinking while the demons are still making their approach. And this incredible thought Sesshomaru is thinking of is that because Sesshomaru has the ability to make his fangs turn bright green as a giant dog demon, that Tetsusaiga should also possess this same power. And while Sesshomaru is thinking this, there is a flashback of Sesshomaru in his giant dog demon form whose fangs are neon green and have neon green rays of light shining from them which are corroding many types of material as Sesshomaru is sinking his toxic bright green fangs into the material which results in the material smoking with toxic bright green smoke.
Once the flashback ended, Sesshomaru makes his Tetsusaiga transform which results in a burst of neon green light (toxic bright green light) as a result of its transformation. Seeing this, Toutousai becomes very surprised and says that the light emitted from Tetsusaiga is different now with an astonished tone of voice. Which then, Sesshomaru becomes exceedingly proud that once again he has been proven correct. Afterwards, Sesshomaru’s Tetsusagia turns bright green (which has toxic bright green rays of light shining from it) and starts to have toxic bright green wind whirling around it--(wind that has absorbed the bright neon green poison from the toxic bright green Tetsusaiga, thus converting this ordinary wind into toxic bright green wind which is extremely hazardous to any opponent who comes into contact with it).
There is then a "rhow-rhow" noise produced as Sesshomaru unleashes the Toxic Wind Scar which results in an incredibly powerful huge burst of neon green light being unleashed (the toxic bright green wind) which makes the entire screen turn bright green as the demons are shown being demolished like acid. And once the toxic bright green wind cleared away, everything is corroded and smoking with toxic bright green smoke and the demolished remains of the demons fall to the ground in a corroded state with the flesh eaten away and the bones being exposed.
Once Sesshomaru has -*test*-('")ed out his reforged Tetsusaiga, he then has a proud smirk on his face and the toxic bright green Tetsusaiga which has toxic bright green wind whirling around it (which not only makes a whirling sound, but also makes a high pitch noise [the sound of light]) disappears and Tetsusaiga returns to its normal color.
Now here's a picture very similar to the color of the toxic bright green wind from Sesshomaru's Toxic Wind Scar:

(NOTE: this is just an ordinary picture of green light. But pretend that this green light is the toxic bright green wind from Sesshomaru’s Toxic Wind Scar because if Sesshomaru were to unleash the Toxic Wind Scar, the toxic bright green wind that is unleashed would be in the form of the green light shown in this picture. But ignore the colors of white and blue in the middle).