GG5: darkish; dusky; murky; dark.
Other JEs similar

I thought it was OK. Aligning with どす is not so important.

@@ -16,5 +16,7 @@
-<xref type="see" seq="2701370">ドス・3</xref>
-<xref type="see" seq="2701370">ドス・3</xref>
-<xref type="see" seq="2701370">ドス・3</xref>
-<gloss>murky black</gloss>
-<gloss>dark ( thoughts, etc. )</gloss>
+<xref type="see" seq="2701370">どす・3</xref>
+<xref type="see" seq="2701370">どす・3</xref>
+<xref type="see" seq="2701370">どす・3</xref>
+<gloss>darkish</gloss>
+<gloss>dusky</gloss>
+<gloss>dark</gloss>
+<gloss>murky</gloss>

sankoku: 色が、黒くてきたない感じだ
どす黒い	47758	67.0%
ドス黒い	22669	31.8%
ドスぐろい	81	0.1%
どすぐろい	786	1.1%

added katakana, changed gloss, trying to align with どす[3].

I have the proviso on "dark":  "( thoughts, etc. )", because I think "dark" would be inadequate if considered as a color alone.

"darkish" and "dusky" don't seem to align with the entry for どす, and don't seem to match google image search results. I see oily black in a lot in images...
Collocations include どす黒い血, どす黒い感情, どす黒いオーラ ドス黒い陰謀
"Dark" as a metaphor seems to be correct for どす黒い感情.  

There is a now-popular book titled 
GACKTのドス黒いメンタリズム  

Reverso has one example ドス黒い曲 =　"thick dark songs" 

Maybe there is a better gloss, but I don't want to get carried away.  

Linked back to どす to let the reader see the various nuances...

@@ -5,0 +6,3 @@
+</k_ele>
+<k_ele>
+<keb>ドス黒い</keb>
@@ -12,2 +15,4 @@
-<gloss>darkish</gloss>
-<gloss>dusky</gloss>
+<xref type="see" seq="2701370">どす・3</xref>
+<xref type="see" seq="2701370">ドス・3</xref>
+<gloss>murky black</gloss>
+<gloss>dark ( thoughts, etc. )</gloss>