Based on Mark Knibbs's 'Colour Bars' demo (which, incidentally, does not work on real hardware), comes an improved palette test program.
Eight consecutive colors are displayed on the screen at once, selectable by pressing Left/Right. Numbers at the top of each column indicate the palette index for each color. The top half of the screen always shows the colors as-is, while the bottom half allows enabling color emphasis (selected by pressing Up/Down, with status indicated in the first column) and/or grayscale mode (toggled by pressing Select). Sprites can be hidden and unhidden by pressing Start.
The ROM can be found at my NES site. It has been tested successfully on Kevin Horton's CopyNES.
Eight consecutive colors are displayed on the screen at once, selectable by pressing Left/Right. Numbers at the top of each column indicate the palette index for each color. The top half of the screen always shows the colors as-is, while the bottom half allows enabling color emphasis (selected by pressing Up/Down, with status indicated in the first column) and/or grayscale mode (toggled by pressing Select). Sprites can be hidden and unhidden by pressing Start.
The ROM can be found at my NES site. It has been tested successfully on Kevin Horton's CopyNES.