The decision to sell a home is and will always be an undertaking few want to do. From the contractors perspective, I personally dislike with prejudice when a soon to be new homeowner or about to vacate homeowner calls for an estimate. 99% of the time they are calling me too late and there isn't a way for me to meet their time line to get the house on the market or to get them into the home after closing.
#1 - Call early - shoot call before you call a realtor if you have to. If you think there is a possibility that the work needs to get done as a contingency to the house sale. You need to call early so that a contractor can fit you in the calendar. MOST GOOD CONTRACTORS ARE 3-6 MONTHS OUT. If you find one that can do the work within' a 7 day period to when you contacted them, It should be a massive red flag, ie. "why is this person not busier?"
#2 - Poke at it
No one is excited to find deficiencies in their home. But just closing the door or not looking at it won't make it go away. If you see something. call someone.
#3 Your color isn't the color they want
And last, every single homeowner enters their new home and wonders "why did the previous owner do "x"?" - every time every home. You aren't trying to get it perfect. You're trying to make it sellable.