Pixel color replacement - in a pixel art context -.

Well, it seems to work! Thank you for the hint. However the lighting seems to be broken... how can I use a shader like this on an unlit texture ?

 // Unlit_$$anonymous$$yCharacter shader. ($$anonymous$$odified from Unlit/Normal)
 // Change _ShirtColor / _NameColor / _NumColor to compose your shirt.
 
 Shader "Unlit/$$anonymous$$yCharacter" {
 Properties {
     _$$anonymous$$ainTex ("Base (RGB)", 2D) = "white" {}
     _ShirtTex ("ShirtTex(RGB)", 2D) = "white" {}
     _ShirtColor ("ShirtColor", Color) = (1,1,1,1)
     _NameColor ("NameColor", Color) = (1,0,0,1)
     _NumColor ("NumColor", Color) = (0,1,0,1)
 }
 
 SubShader {
     Tags { "RenderType"="Opaque" }
     LOD 100
     
     Pass {  
         CGPROGRA$$anonymous$$
             #pragma vertex vert
             #pragma fragment frag
             
             #include "UnityCG.cginc"
 
             struct appdata_t {
                 float4 vertex : POSITION;
                 float2 texcoord : TEXCOORD0;
             };
 
             struct v2f {
                 float4 vertex : SV_POSITION;
                 half2 texcoord : TEXCOORD0;
             };
 
             sampler2D _$$anonymous$$ainTex;
             float4 _$$anonymous$$ainTex_ST;
             sampler2D _ShirtTex;
             float4 _ShirtTex_ST;
             float4 _ShirtColor;
             float4 _NameColor;
             float4 _NumColor;
             
             v2f vert (appdata_t v)
             {
                 v2f o;
                 o.vertex = mul(UNITY_$$anonymous$$ATRIX_$$anonymous$$VP, v.vertex);
                 o.texcoord = TRANSFOR$$anonymous$$_TEX(v.texcoord, _$$anonymous$$ainTex);
                 return o;
             }
             
             fixed4 frag (v2f i) : COLOR
             {
                 fixed4 col = tex2D(_$$anonymous$$ainTex, i.texcoord);
                 fixed4 col2 = tex2D (_ShirtTex, i.texcoord);
 
                 //change code blow if need any detail in _$$anonymous$$ainTex
                 col = lerp(col, _ShirtColor, col2.r);//change area in red to _ShirtColor
                 col = lerp(col, _NameColor, col2.g);//change area in green to _NameColor
                 col = lerp(col, _NumColor, col2.b);//change area in blue to _NumColor
 
                 return col;
             }
 
         ENDCG
     }
 }
 
 }
 

Hey, thanks again for the answer. I'm not sure it works as I thought :(

As I understand your shader it will look for colors that contain "Red" and change them by "_ShirtColor" value... it only works with full Red, full Blue... right? How to make it work with specific colors to perform something like "Change every pixel of (100,12,168) color by (22,33,55) color" ?

Thanks again for your help.

No, it can change any area not only the solid color. And you dont know why i left the _$$anonymous$$ainTex.

Note that : col = lerp(col, ShirtColor, col2.r); It means : Change color in $$anonymous$$ainTex if point with same coordinate in ShirtTex is red, or keep the color in $$anonymous$$ainTex.

You should Add your origin tex as _$$anonymous$$ainTex, and copy a tex as _ShirtTex. Then Change the shirtArea/nameArea/numArea color to solidcolor in _ShirtTex.

As you said, if you want change all pix of (100,12,168), you should change all pix with the color in _ShirtTex to red, and set _ShirtColor to (22,33,55).

if more than 4 colors need change, Do Not Use"change a as b", conclude them as a func and change "lerp" to you func.

At last, sorry for my poor English.

I'm really sorry but I still don't get it (once again, I suck a shaders :/).

Here is my original plan : having two textures, one of the shirt and another one with a "palette" ( a grid of 16xN color, where 16 is the number of color available on the shirt texture, and N the number shirt color skin possible ie: if [0][0] is white and [1][0] is blue, then every white pixels of the original shirt will be blue when player selects the second set of colors available ).

So yes, there will be obviously more than 4 colors to change.

This is surely why I still don't manage to understand what you're trying to explain me (and I'm sorry about that). Do you think this technique (using a palette and a texture to change) can be doable via shaders ?

(once again thanks for your help)