Back to work on the brakes on my Coronet. I have the Dr Diff 13" front/11.75 rear with 15/16" Master. It's been a fiqht to get system filled/bled but finally making headway. I originally bought a quart of DOT 5 from NAPA, getting a little low so decided to grab another bottle, got home and opened a sealed bottle and the color is dark green where the first was bright purple. It's an hour and a half round trip to get another. Should I use it or wait until I can get another bottle? I poured some into my Motive power bleeder bottle and the two mixed looks black, not sure I want to introduce that into the system.