My question basically is: since we know that ke'samim do not apply when on colored clothing it would seem to be that it does not apply to colored anything else either.
However the gemara seems to say cases like skin-where it is certainy colored (in black people but also in whites like us) but also in the case of mashtisa where the wood is certainy not bleached white. Also the case of karka olam is referring to regular ground which is also white. So all these examples seem to indicater that the heter for colored is only on clothing . However no one seems to make that chiluk. ASs a matter of fact the Ra,mbam sounds like it applies to keilim too-the heter odf colored so therefore I think we have a contradiction.
Gut Shabbos Shmuel
[This response should not be construed as a Halachic ruling on the question. Rather, it is an exploration of the topic to help our readers become more familiar with the issues involved.]
Without discussing the woman's own skin (as there would be more room for stringency in many cases), there is in fact an argument among the Poskim regarding skins (see Badei Hashulchan 190:111). Regarding the case of Mashtisa and Karka there are two possible answers. One possibility is that these examples are indeed white. Alternatively, they are not white but very lightly colored. This would be in accordance with the view of some Poskim who say that very light colors of clothing, where the redness of the blood can still be clearly determined, are also "Mekabel Kesamim." The Poskim generally seem to hold, as you stated, that there is no difference between clothing and other colored items.
[I hope this response has clarified the issue. For all practical questions on the issue, please consult your local Orthodox rabbi.]
All the best,
Yaakov Montrose