You are not a true fan of The Witcher 3 game if you do not know who Vesemir is. He is, after all, one of the characters with an interesting and significant role in the lore. While everyone knows him being much older and beaten down, a mode was made and designed to give the old man his old concept variant.
In the original concept art for the CD Projekt Red’s title, Vesemir’s color combination on his armor was much brighter. The shoulder pads and pants leaned toward a beiger and more vibrant brown; he even had a red tunic tucked underneath. He simply looked grumpy, fitting his grandfather role. In the final and official build, however, the veteran Witcher has more muted colors specifically on his armor, giving him a washed-out or used appearance – a description fitting for being the experienced and wise Witcher he is also known for.
One fan really loved the concept variant of The Witcher 3 character that they created a mod so it can be added into The Witcher 3’s next-gen update. Though Vesemir retains his older appearance, he now has a thinner face and more wrinkles. His clothing is brighter and even his entire color scheme looks like the aforementioned concept art. The mod really gives a near-perfect replica of the original character design. One could even argue that it fits perfectly in the more colorful world of The Witcher 3.
The concept art states that they wanted to go for Vesemir’s indescribable age. While he is certainly a very old sod, it is hard to tell how old he really is - nobody really knows. Sure, he has been around for a while, but only his armor can really reflect that. This is also why the Concept Vesemir mod by cnfilmm was created. It is meant to recolor Vesemir’s armor, improve his leather and armor detail, and rework the character’s face textures.
It is worth noting that in order for fans and players to use the mod, they need to own both the Blood and Wine and Hearts of Stone DLCs. Otherwise, it will not work at all.