adding texture to vertex color darkens color

Hi I am trying to make my own simple shader for matching color of the background with color of my objects(clifs). Its all for doing chasms, or pitfalls that blend to one color.

Adding only vertex color to shaders(binding) gives accurate color: shader code:

 Shader "Custom/VColDiffBlnd" {
     Properties {
         _MainTex ("Base (RGB)", 2D) = "white" {}
     }
     
     SubShader {
         BindChannels {
             bind "color", color
             Bind "vertex", vertex
             Bind "TexCoord", texcoord
         }

     }

but when adding setTexture it darkens the texture.

 Shader "Custom/VColDiffBlnd" {
     Properties {
         _MainTex ("Base (RGB)", 2D) = "white" {}
     }
     
     SubShader {
         BindChannels {
             bind "color", color
             Bind "vertex", vertex
             Bind "TexCoord", texcoord
         }
         pass {
             SetTexture[_MainTex] {
                  Combine texture * primary
                 }
         }
     }

And i know that is normal, but is there a way to add my color to the texture and preserving the bright color of both of them(texture and vertex color)?

And i cant make one gradient or alpha map to use in this because this shader will be used for different textures with different uv coords.

Should I double(or quad) primary? But How?