Oil Color

So currently running a 440, .30 over, Edlebrock alum heads, mild cam, alum intake, forged internals. Motor cant have more then 400 hundred miles since it was built many moons ago( 17 years), car sat but was ran monthly since its inception. Motor is really strong , sounds great, great oil pressure at start up and idle. One of my concerns lies in the color of the oil. I have started driving the car recently and have so far put maybe 150 miles on it since it had sat for the better part of a decade. I did pull the pan and clean everything out really good, but after running fresh clean oil for a short period, I pull the stick and its basically black ( this is the 3rd oil change in less then 150 miles. The oil looks like its got 10k on it. Before the carbs were rebuilt there was a good amount of gas in the crankcase, That problem was obviously solved before i started driving and running the car. Any thoughts? Could I just have residual sludge in the motor that has not completely worked itself down to the pan? Just want to avoid a larger problem due to avoiding asking. As always thank you all in advance for the help.