He said the colors don't match with his decors.

(actually, 2 lessons... get it in writing and never rent anyplace that thinks saloon doors are a good decorating idea)

I don't want him inspecting my decorating skills or noticing what I had for breakfast.  

Yet, they have a say in what happens to your investment, and how you can use it, or decorate it, and they can vote in special assessments that you don't want, but you have to pay for anyway.Buy something free and clear that you can control, and with normal costs that you can reasonably predict.  

Also, for less than $40, you could buy faux decorative black hinges and handles to add some interest to the garage door.Then, like others have mentioned, a white window box filled with colorfull flowers, a pair of shepherd hooks with two matching flower baskets, and some dark mulch, would add punch.I used photoshop to create a picture of what I'm describing.Best of luck with your flip!

Therefore; if you are decorating a home using the influence of Mid Century Modern, or Modern, you wouldn't need to be as careful, but would be looking more toward getting that vibe, with new colors and furnishings that are currently popular but influenced by that era. 

You could place something decorative there (glass, an adhesive, artwork) to give the viewer a sense that they are looking at or out a window. 

That would be a tank big enough to decorate, have multiple fish to watch, etc.  

"Reclaimed" wood is all the rage in furniture and decor right now.The diabetic strip thing has been discussed here before.  

I've decorated my places like Hugh Hefner's mansion.  2000 previous renters and no complaints