Added helper sampler function and conversion between colorspaces.

Assets/ScriptableRenderPipeline/LightweightPipeline/Shaders/LightweightPipeline.shader

 
             half4 frag(v2f i) : SV_Target
             {
-                half4 diffuseAlpha = tex2D(_MainTex, i.uv01.xy);
+                half4 diffuseAlpha = Tex2DLinearRGBA(_MainTex, i.uv01.xy);
                 half3 diffuse = diffuseAlpha.rgb * _Color.rgb;
                 half alpha = diffuseAlpha.a * _Color.a;
 

Assets/ScriptableRenderPipeline/LightweightPipeline/Shaders/LightweightPipelineCore.cginc

 #define _SHADOW_CASCADES
 #endif
 
+
+#if (defined(UNITY_COLORSPACE_GAMMA) || SHADER_TARGET < 30) && defined(LIGHTWEIGHT_FORCE_LINEAR)
+// Ideally we want an approximation of gamma curve 2.0 to save ALU on GPU but as off now it won't match the GammaToLinear conversion of props in engine
+//#define LIGHTWEIGHT_GAMMA_TO_LINEAR(gammaColor) gammaColor * gammaColor
+//#define LIGHTWEIGHT_LINEAR_TO_GAMMA(linColor) sqrt(color)
+#define LIGHTWEIGHT_GAMMA_TO_LINEAR(sRGB) sRGB * (sRGB * (sRGB * 0.305306011h + 0.682171111h) + 0.012522878h)
+#define LIGHTWEIGHT_LINEAR_TO_GAMMA(linRGB) max(1.055h * pow(max(linRGB, 0.h), 0.416666667h) - 0.055h, 0.h)
+#else
+#define LIGHTWEIGHT_GAMMA_TO_LINEAR(color) color
+#define LIGHTWEIGHT_LINEAR_TO_GAMMA(color) color
+#endif
+
 struct LightInput
 {
     half4 pos;
 #include "LightweightPipelineShadows.cginc"
 #endif
 
+inline half3 Tex2DLinearRGB(sampler2D s, half2 uv)
+{
+    return LIGHTWEIGHT_GAMMA_TO_LINEAR(tex2D(s, uv).rgb);
+}
+
+inline half4 Tex2DLinearRGBA(sampler2D s, half2 uv)
+{
+    half4 color = tex2D(s, uv);
+    return half4(LIGHTWEIGHT_GAMMA_TO_LINEAR(color.rgb), color.a);
+}
+
 inline void NormalMap(v2f i, out half3 normal)
 {
 #if _NORMALMAP
 inline void SpecularGloss(half2 uv, half alpha, out half4 specularGloss)
 {
 #ifdef _SPECGLOSSMAP
-    specularGloss = tex2D(_SpecGlossMap, uv) * _SpecColor;
+    specularGloss = Tex2DLinearRGBA(_SpecGlossMap, uv) * _SpecColor;
-    specularGloss = tex2D(_SpecGlossMap, uv) * _SpecColor;
+    specularGloss = Tex2DLinearRGBA(_SpecGlossMap, uv) * _SpecColor;
     specularGloss.a = alpha;
 #else
     specularGloss = _SpecColor;
 inline void Emission(half2 uv, inout half3 color)
 {
 #ifdef _EMISSION
-    color += tex2D(_EmissionMap, uv) * _EmissionColor;
+    color += Tex2DLinearRGB(_EmissionMap, uv) * _EmissionColor;
 #else
     color += _EmissionColor;
 #endif
 {
 #ifdef _ALPHABLEND_ON
-    return half4(color, alpha);
+    return LIGHTWEIGHT_LINEAR_TO_GAMMA(half4(color, alpha));
-    return half4(color, 1);
+    return half4(LIGHTWEIGHT_LINEAR_TO_GAMMA(color), 1);
 #endif
 }