tests/ref/vsynth: fix fate colr changes

Commit 9842fd3a stopped guessing colr
values.
Signed-off-by: Michael Bradshaw <mjbshaw@google.com>

tests/ref/vsynth/vsynth1-dnxhd-1080i-colr

-2caca2edcb519c88543c38e129ded03b *tests/data/fate/vsynth1-dnxhd-1080i-colr.mov
+5571f4ff9e29d352a7e373a14a9ed2ed *tests/data/fate/vsynth1-dnxhd-1080i-colr.mov
 3031929 tests/data/fate/vsynth1-dnxhd-1080i-colr.mov
 6f2d5429ffc4529a76acfeb28b560542 *tests/data/fate/vsynth1-dnxhd-1080i-colr.out.rawvideo
 stddev:    5.65 PSNR: 33.09 MAXDIFF:   55 bytes:  7603200/   760320

tests/ref/vsynth/vsynth2-dnxhd-1080i-colr

-e7e5cd8d6d1596596ded1007f37c3193 *tests/data/fate/vsynth2-dnxhd-1080i-colr.mov
+eee674d012c850c1d2bb5e816b668cdf *tests/data/fate/vsynth2-dnxhd-1080i-colr.mov
 3031929 tests/data/fate/vsynth2-dnxhd-1080i-colr.mov
 ec40a8014b819d02951b2f06bee7b514 *tests/data/fate/vsynth2-dnxhd-1080i-colr.out.rawvideo
 stddev:    1.54 PSNR: 44.33 MAXDIFF:   33 bytes:  7603200/   760320

tests/ref/vsynth/vsynth3-dnxhd-1080i-colr

-f5a7d7f837a750784458c60fb7b4d091 *tests/data/fate/vsynth3-dnxhd-1080i-colr.mov
+92a2f67cf77abf3428fe2d4f53ba2027 *tests/data/fate/vsynth3-dnxhd-1080i-colr.mov
 3031929 tests/data/fate/vsynth3-dnxhd-1080i-colr.mov
 f907fd2d48bedbc5283fbfc3fb9f61a0 *tests/data/fate/vsynth3-dnxhd-1080i-colr.out.rawvideo
 stddev:    6.92 PSNR: 31.32 MAXDIFF:   50 bytes:    86700/     8670