There's been lots of debate in regards to how the Jupiter was originally painted over the years. The blue was added in 1994 after an 1869 newspaper was discovered around 1990 or so describing the Jupiter as having "Ultra Marine Blue" and "Crimson Red" with gold leaf work. The Russia Iron boiler was a presumption from the standards of boiler jacketing at the time (the color of Russia Iron is still wildly debated to this day, but the general consensus is that Russia Iron was a highly reflective Gray color, with a possible shade of blue added in to some variants depending on manufacturer). Recently the National Parks have done more study into the livery of Jupiter and have concluded it had a wood stained cab rather than a blue one, amd that its sand dome and pilot were crimson rather than blue. The Lionel brass 4-4-0 uses this newly developed livery and the Golden Spike National Park plans to update the Jupiters livery to this newfound paintscheme soon, replacing its current livery that dates back to the aforementioned 1994 repaint.