https://testimages.org/color/Firefox complained about https but opened the site==== from description ====For every resolution listed above and for both 8bpp and 16bpp, the following 7 images were generated:
color_bars_CMYKWRGB: Eight vertical bars at maximum intensity (255 for 8bpp and 65535 for 16bpp) representing different colors in the following order: Cyan (Green + Blue), Magenta (Red + Blue), Yellow (Red + Green), Black, White (Red + Green + Blue), Red, Green, Blue.color_bars_CMYKWRGB_100IRE: Variation of the color_bars_CMYKWRGB where the minimum intensity level is set to 7.5IRE (16 for 8 bit, 4096 for 16 bit) and the maximum intensity level is set to 100IRE (235 for 8 bit, 60160 for 16 bit).color_bars_CMYKWRGB_75IRE: Variation of the color_bars_CMYKWRGB where the minimum intensity level is set to 7.5IRE (16 for 8 bit, 4096 for 16 bit) and the maximum intensity level is set to 75IRE (180 for 8 bit, 46144 for 16 bit).color_bars_CMYKWRGB_gradient: Variation of the color_bars_CMYKWRGB where intensity levels varies linearly from top 0% to bottom 100%.color_rainbow: Six vertical color sections with the following intensity variations to obtain a "rainbow" effect: 1. red=MAX, green=0 to MAX, blue=0; 2. red=MAX to 0, green=MAX, blue=0; 3. red=0, green=MAX, blue=0 to MAX; 4. red=0, green=MAX to 0, blue=MAX; 5. red=0 to MAX, green=0, blue=MAX; 6. red=MAX, green=0, blue=MAX to 0.color_rainbow_gradient: Variation of the color_rainbow where intensity levels varies linearly to obtain a black to white variation from top to bottom.color_SMPTE_RP_219_2002: This image is generated as described in SMPTE RP 219:2002 and resized to perfectly match different resolution.===download link lead to sourceforgeIf you click on small "i" you get filesize, usually not very big (500 kb or so)