Transparent Cube with Colored Edge lines

How would I go about making a transparent cube with Colored Edge lines? So if an object was inside, it would look like it was surrounded by the edge lines of the cube.

You could use a shader with -culling off- and transparency. Then make a texture with only edges colored and rest is transparent. Map the texture to your cube faces. random shader example:

Shader "UnlitAlpha" { Properties { _Color ("Main Color", Color) = (1,1,1,1) _MainTex ("Base (RGB) Trans. (Alpha)", 2D) = "white" { } }

Category
{
    ZWrite On
    Alphatest Greater 0.5
    Cull Off
    SubShader
    {
        Pass
        {
            Lighting Off
            SetTexture [_MainTex]
            {
                constantColor [_Color]
                Combine texture * constant, texture * constant
            }
        }
    }
}

}

Couldn't you just model that shape in your 3D software?