pale blue vs light-blue

pale blue and light-blue both are adjectives.

Word	Noun	Adjective	Verb	Adverb
pale blue	No	Yes	No	No
light-blue	No	Yes	No	No

As adjectives, pale blue and light-blue are synonyms defined as:

pale blue (adjective)	light-blue (adjective)
of a light shade of blue	of a light shade of blue