Need to change color of a texture

Hello

Is it possible that I can change the color of a part of a texture with this (Color thing - Album on Imgur) texture? I want the black to be the stuff that get’s changed from the original (Color thing - Album on Imgur scroll down a bit) texture. So I can only color the body part of the vehicle instead of using diffuse which colors the whole car.

If it’s unclear, please tell me and I will explain it more.

It can be done with shader coding. When you use build-in standard shaders you can write your own shaders. in this case you can simple write a surface shader like this and apply the albedo and mask texture:

Shader "Custom/MaskShader"
{
    Properties
    {
        _Color ("Color", Color) = (1,1,1,1)
        _MainTex ("Albedo (RGB)", 2D) = "white" {}
		_MaskTex("Maks (RGB)", 2D) = "white" {}
        _Glossiness ("Smoothness", Range(0,1)) = 0.5
        _Metallic ("Metallic", Range(0,1)) = 0.0
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 200

        CGPROGRAM
        // Physically based Standard lighting model, and enable shadows on all light types
        #pragma surface surf Standard fullforwardshadows

        // Use shader model 3.0 target, to get nicer looking lighting
        #pragma target 3.0

        sampler2D _MainTex;
		sampler2D _MaskTex;

        struct Input
        {
            float2 uv_MainTex;
        };

        half _Glossiness;
        half _Metallic;
        fixed4 _Color;

        // Add instancing support for this shader. You need to check 'Enable Instancing' on materials that use the shader.
        // See https://docs.unity3d.com/Manual/GPUInstancing.html for more information about instancing.
        // #pragma instancing_options assumeuniformscaling
        UNITY_INSTANCING_BUFFER_START(Props)
            // put more per-instance properties here
        UNITY_INSTANCING_BUFFER_END(Props)

        void surf (Input IN, inout SurfaceOutputStandard o)
        {
            // Albedo comes from a texture tinted by color
            fixed4 c = tex2D(_MainTex, IN.uv_MainTex)*(1-tex2D(_MaskTex, IN.uv_MainTex)) + tex2D (_MainTex, IN.uv_MainTex) * tex2D(_MaskTex, IN.uv_MainTex)*_Color;
            o.Albedo = c.rgb;
            // Metallic and smoothness come from slider variables
            o.Metallic = _Metallic;
            o.Smoothness = _Glossiness;
            o.Alpha = c.a;
        }
        ENDCG
    }
    FallBack "Diffuse"
}

173859-mask.png

Here are some learningresources:

Unity manual about writing surface shaders
Unitys overview of writing surface and vertex/fragment shaders

If you are using different renderpipelines like URP or HDRP there is a free visual shader programming tool from Unity called ShaderGraph.

Unity Shader Graph introduction

A good tool in current build-in renderpipeline for people with less knowledge on shader programming to understand and learn shaderprogramming might be a visual shader programming tool like Amplify Shader Editor.

are you talking about changing the color in unity or in some art program?