http://www.simplesystems.org/users/bfriesen/dpx/ contains three dpx samples, one (16 bit) looks ugly with FFmpeg, ImageMagick and GraphicsMagick, the other two (8 bit) only look broken with FFmpeg.
$ ffmpeg -i DLAD_8b_1c_big.dpx
ffmpeg version N-63624-g4ba8560 Copyright (c) 2000-2014 the FFmpeg developers
built on May 31 2014 12:24:49 with gcc 4.7 (SUSE Linux)
configuration: --enable-gpl
libavutil 52. 87.100 / 52. 87.100
libavcodec 55. 65.100 / 55. 65.100
libavformat 55. 42.100 / 55. 42.100
libavdevice 55. 13.101 / 55. 13.101
libavfilter 4. 5.100 / 4. 5.100
libswscale 2. 6.100 / 2. 6.100
libswresample 0. 19.100 / 0. 19.100
libpostproc 52. 3.100 / 52. 3.100
Input #0, image2, from 'DLAD_8b_1c_big.dpx':
Duration: 00:00:00.04, start: 0.000000, bitrate: N/A
Stream #0:0: Video: dpx, gray, 255x185 [SAR 1:1 DAR 51:37], 25 tbr, 25 tbn, 25 tbc
At least one output file must be specified
$ ffmpeg -i DLAD_8b_3c_big.dpx
ffmpeg version N-63624-g4ba8560 Copyright (c) 2000-2014 the FFmpeg developers
built on May 31 2014 12:24:49 with gcc 4.7 (SUSE Linux)
configuration: --enable-gpl
libavutil 52. 87.100 / 52. 87.100
libavcodec 55. 65.100 / 55. 65.100
libavformat 55. 42.100 / 55. 42.100
libavdevice 55. 13.101 / 55. 13.101
libavfilter 4. 5.100 / 4. 5.100
libswscale 2. 6.100 / 2. 6.100
libswresample 0. 19.100 / 0. 19.100
libpostproc 52. 3.100 / 52. 3.100
Input #0, image2, from 'DLAD_8b_3c_big.dpx':
Duration: 00:00:00.04, start: 0.000000, bitrate: N/A
Stream #0:0: Video: dpx, rgb24, 255x185 [SAR 1:1 DAR 51:37], 25 tbr, 25 tbn, 25 tbc
At least one output file must be specified
DLAD_8b_3c_big.dpx is supposed to be decoding with R and B swapped, as evidenced by 2 other software, GraphicsMagik and XnView.
There are various interesting metadata left to parse, like colorspace and orientation but that's irrelevant to this bug.
Fixed in 4ba45c189ccafdedcdb703e40441fbd24fe62989 then.