Question about blender and unity

With 3d modeling, blender is a reliable tool to use with unity. But I have never been able to color objects in blender and have that color show up in unity. Is there a way to export an object’s vertex color to unity? Or will I need to use uv textures, and if so where can I go to learn how to do this?

You have to use a specific shader. A vertex shader which has to use vertex color information. Here a simple one :

Shader "Custom/VertexColor" {
    SubShader {
    Pass {
        LOD 200
         
        CGPROGRAM
        #pragma vertex vert
        #pragma fragment frag
 
        struct VertexInput {
            float4 v : POSITION;
            float4 color: COLOR;
        };
         
        struct VertexOutput {
            float4 pos : SV_POSITION;
            float4 col : COLOR;
        };
         
        VertexOutput vert(VertexInput v) {
            VertexOutput o;
            o.pos = mul(UNITY_MATRIX_MVP, v.v);
            o.col = v.color;
             
            return o;
        }
         
        float4 frag(VertexOutput o) : COLOR {
            return o.col;
        }
 
        ENDCG
        }
    }
 
}