Walters F-40ph review

Have just picked up a Walters Mainline F40ph in phase IV,the trucks and underframe is painted silver,am tempted to paint the
trucks and underframe equipment flat black.
Silver tends to show dirt and not hold up well over time at track level,For the Santa Fe Chief and Super Chief,both the F-7's and
passenger car trucks got touched up or repainted at LA and Chicago,to a point that sandblasting off the paint layers was needed to
do repairs/replace parts.
Only a very few F40's saw ph IV paint applied,did Beech Grove really paint the trucks and underframe gear silver?