sulfur-yellow vs sulphur-yellow

sulfur-yellow and sulphur-yellow both are adjectives.

Word	Noun	Adjective	Verb	Adverb
sulfur-yellow	No	Yes	No	No
sulphur-yellow	No	Yes	No	No

As adjectives, sulfur-yellow and sulphur-yellow are synonyms defined as:

sulfur-yellow and sulphur-yellow: of something having the yellow color of sulfur

sulfur-yellow (adjective)	sulphur-yellow (adjective)
of something having the yellow color of sulfur	of something having the yellow color of sulfur