without negate option, but replaced

[tsuzu]

I use ImageMagick 6.5.7 on windows to convert from PDF to EPS, which command is "convert -trim aaa.pdf aaa.eps"
Those PDF are almost based on Photo and illustration.

Now, some EPS is replaced each pixel with its complementary color without negate option.
So I do use "negate option" , and that is converted appropriately.
I do not know why those EPS is replaced without negate option.
Could you show me the condition that ImageMagick replace its color without option.

Thanks in advance.

[fmw42]

your pdf files may be cmyk format, so try

convert -colorspace rgb aaa.pdf -trim aaa.eps

[tsuzu]

Thanks to you, I can solve the problem !
Those PDF are CMYK format as you said. Thank you very much!