Preferences, display settings, colors - can't select prefered color

I like to capture a screen shot of the map of sites where I wish to correct the osm and add to my iphone gps for offline use.
In josm using a filter I can highlight ‘unamed highways’. They are selected in a charcoal color. - I would prefer yellow.
Using the validator I can choose ‘unamed ways’. These were displaying in yellow but in the past day have decided to paint in dark blue. I would prefer yellow.
In the ‘Display Settings - colors’ setting I unable to set either of these to yellow, though I am able to change some colors of some of the choices.
All I want is to display either of these to yellow for easier visual use on my cycle.
I am using IMac 10.6.8 snow leopard, java 6.x (can’t move to 7 on this mac), in Josm map paint styles the default josm internal style and potlach 2 are checked.
Any pointers please.

fixed… I changed the color setting BEFORE downloading the osm and this fixed the validator back to yellow.
but would still like to know which setting allows changing of the color the Filter uses.