Define a background-color inside an unlit shader

[xPascal97x]

So i have this dotted pattern shader that i’ve been working on for a little bit now. Added a color input for the dot color but i can’t figure out how to set a color input for the background color (in this case black) behind the dots. Probably a newbie question but i really don’t know how.

This is the dotted pattern and i want a color input for the black. I already added a property and identifier for it but i don’t know where i would have to add it inside the fragment shader.

Shader "Unlit/Dotted Pattern"
{
    Properties
    {
        [HideInInspector]_MainTex ("Texture", 2D) = "white" {}
        [HDR]_DotColor ("Dot Color", Color) = (1,1,1,1)
        [HDR]_BgColor ("Background Color", Color) = (1,1,1,1)
        _DotsAngle ("Dots Angle", float) = 45
        _DotSize ("Dot Size", range(10,100)) = 30
        _DotShape ("Dot Shape", range(0.01,0.99)) = 0.1
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 100
        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            // make fog work
            #pragma multi_compile_fog
            #include "UnityCG.cginc"
            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };
            struct v2f
            {
                float2 uv : TEXCOORD0;
                UNITY_FOG_COORDS(1)
                float4 vertex : SV_POSITION;
            };
            sampler2D _MainTex;
            float4 _MainTex_ST;
            float4 _DotColor;
            float4 _BgColor;
            float _DotsAngle;
            float _DotSize;
            float _DotShape;
            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                UNITY_TRANSFER_FOG(o,o.vertex);
                return o;
            }
            static float PI = 3.1415926535897932384626433832795;
            static float PI180 = float(PI / 180.0);
            float sind(float a)
            {
                return sin(a * PI180);
            }
            float cosd(float a)
            {
                return cos(a * PI180);
            }
            float added(float2 sh, float sa, float ca, float2 c, float d)
            {
                return 0.5 + 0.25 * cos((sh.x * sa + sh.y * ca + c.x) * d) + 0.25 * cos((sh.x * ca - sh.y * sa + c.y) * d);
            }
            fixed4 frag (v2f i) : SV_Target
            {
                float threshold = clamp(float(_ScreenParams.x / _ScreenParams.x) * 0.99, 0, 1);
                float ratio = _ScreenParams;
                float coordX = i.uv.x;
                float coordY = i.uv.y;
                float2 dstCoord = float2(coordX, coordY);
                float2 srcCoord = float2(coordX, coordY / ratio);
                float2 rotationCenter = float2(0, 0);
                float2 shift = dstCoord - rotationCenter;
   
                float dotSize = _DotSize;
                float angle = _DotsAngle;
   
                float rasterPattern = added(shift, sind(angle), cosd(angle), rotationCenter, PI / dotSize * 680.0);
                float4 srcPixel = tex2D(_MainTex, srcCoord);
       
                float avg = _DotShape;
                float4 col = (1, 1, 1, 1) * _DotColor;
                float gray = (rasterPattern * threshold + avg - threshold) / (1.0 - threshold);
                return float4 (gray, gray, gray, 1.0) * col;
            }
            ENDCG
        }
    }
}

[unityuserunity85496]

shaders are simply numbers 0 to 1 that you use arithmetic to get values. A color is just rgb or a vector3 float,half,fixed are precision stores for the vector3(4)
Soooo you can add any color + color together to get some value. So adding 0 (black) to 0.5 grey gives grey. And Adding 1 to 0.5 gives 1.5. The renderer clamps any values between 0 to 1 when you’re done.