That color really probably shouldn't be in use in that model (which is an LDView sample model, created by Peter Bartfai, LDView's Qt version maintainer). However, it's a transparent direct dither color. If you can read C++ code, you can take a look at LDView's color number processing code in this file, starting at line 462. The code for 0x6xxxxxx color codes starts at line 525.
Here are the "special" colors that LDView handles, all of which have been used at some point in the past:
0x2RRGGBB: opaque RGB direct colors
0x3RRGGBB: transparent RGB direct colors
0x4RGBRGB: opaque RGB dither color (RGBRGB are two 12-bit colors)
0x5RGBxxx: transparent RGB dither (xxx is ignored and treated as fully transparent)
0x6xxxRGB: transparent RGB dither (xxx is ignored and treated as fully transparent)
0x7xxxxxx: invisible
Only 0x2RRGGBB opaque direct colors are officially supported in the spec, and they're only there because the LSC at the time wanted to allow those to be used in patterned parts. Personall, I think that the others should at least be mentioned, even if they are continued to be disallowed in official parts. Note, for the 0x4, 0x5, 0x6, and 0x7 numbers above, the bottom two bits in the 5, 6, and 7 can be thought of as ignore bits for the two components of the RGB dither. When a bit is set to ignore one of the components in the RGB dither, that component is treated as fully transparent.
Here are the "special" colors that LDView handles, all of which have been used at some point in the past:
0x2RRGGBB: opaque RGB direct colors
0x3RRGGBB: transparent RGB direct colors
0x4RGBRGB: opaque RGB dither color (RGBRGB are two 12-bit colors)
0x5RGBxxx: transparent RGB dither (xxx is ignored and treated as fully transparent)
0x6xxxRGB: transparent RGB dither (xxx is ignored and treated as fully transparent)
0x7xxxxxx: invisible
Only 0x2RRGGBB opaque direct colors are officially supported in the spec, and they're only there because the LSC at the time wanted to allow those to be used in patterned parts. Personall, I think that the others should at least be mentioned, even if they are continued to be disallowed in official parts. Note, for the 0x4, 0x5, 0x6, and 0x7 numbers above, the bottom two bits in the 5, 6, and 7 can be thought of as ignore bits for the two components of the RGB dither. When a bit is set to ignore one of the components in the RGB dither, that component is treated as fully transparent.