The wall may have the same texture as the rest, but it's just not getting enough light.
Remember, Max re-creates 'real world' situations.....or as close as possible, as does the renderer you use. You need to understand a little how light reacts in this situation......at the moment all you have is light coming in from the 'hole', (as max sees it), therefore it will not illuminate the wall that 'hole' is in......directly.
Light 'bounces' off objects, and as a result illuminates other objects....which bounce it again....etc. The energy of the light decreasing each time it 'bounces' off something. The amount the light decreases depends on the surface properties of the object.....as an example darker surfaces bounce less light than lighter ones......rougher surfaces less than smooth ones...etc.
The vast amount of properties in both the materials and the renderer settings reflect the fact that you need to think a little about whats happening in your scene, ie. where the light is coming from, what will it illuminate and what is it going to bounce off.
Your problem is simply a lighting and render setting issue, but as its a very involved subject it would be wrong of me of to try and explain it here.....you'll learn more by finding out for yourself.
Read the manual. Look for 'Radiosity', 'Global Illumination', 'Light rays'.....etc. Google around for how light works and what it actually is....and does.
Once you have a better understanding of the 'principles' of light, in the real world, then re-creating that situation in a 3D environment will become much easier.....you'll look at this image again and realise just what the problem is and how to solve it.
It's like driving a car....you've got the engine running, now you just need to learn how to make it go forward.
Regards.