Lowes and/or Home Depot have pre-made (connectors at each end) 25 ft 6 conductor line in a package for less than $10. Don't remember the exact price. Just cut off the required length and put connectors on it. I have a bunch of cables made from this stuff. Color is off white and not black. You can get the RJ-11 modular connector in 25 piece packages there too. Just made sure you get the connectors oriented correctly, i.e., inverted relative to each other.