Coppercohne:
Yes white paper is fine, use light source that is daylight:
Full sun and open shade, not a LED, lamp, etc.
The gold std for color match is 5600 K daylight.
Eyes may be the ssue: Variations in color preception over time or between the two eyes is common and indicitave of cataracts.
If you are over 50yrs suggest to see and Opthalamist eye doctror for a full exam.
The usual progression is very slow, over many years. first sign is blurring and glare at night and loss of violet /blue colot
In the end stage you habe a yello or brown cast and poor visiion for driving.
After my cateract operation 10yeas ago, a new world of light and color was revealed.
Take case,
Jon
Sugget