Here I've tried to group some pieces together that exhibit a fair amount, to a lot of chromaticism.

Hawthorne Early Music editions: chromatic scores

Composer	Title	Subtitle	# Parts	Language	Mode	Files
Nicola Vicentino (1511-c.1576)	L'aura che 'l verde lauro et l'aureo crine	Prima parte	5	italian	Hypodorian	Score + Parts
Mattias Greiter (c.1494-c.1550)	Passibus Ambiguis - Fortuna Desperata	Pars prior	4	instrumental	Lydian	Score + Parts
Giuseppe Caimo (c.1545-1584)	E ben ragion se l'eterno mottore		5	italian	Dorian	Score + Parts
Luca Marenzio (c.1553-1599)	O pietà somma	Seconda parte	5	italian	Ionian	Score + Parts
Luca Marenzio (c.1553-1599)	O voi che sospirate a miglior' note		5	italian	Phrygian	Score + Parts
Luca Marenzio (c.1553-1599)	O fere stelle		6	italian	Dorian	Score + Parts
Luca Marenzio (c.1553-1599)	O fido, o caro Aminta		5	italian	Phrygian	Score + Parts
Luzzasco Luzzaschi (1545-1607)	Quivi sospiri pianti ed alti guai		5	italian	Hypodorian	Score + Parts
Andrea Gabrieli (c.1532-1585)	Non vedi o sacr'Apollo		5	italian	Dorian	Score + Parts
Andrea Gabrieli (c.1532-1585)	I' vo piangendo	Prima parte	6	italian	Phrygian	Score + Parts
Leonard Meldert (c.1535-1610)	Tirsi morir volea		5	italian	Dorian	Score + Parts
Giovanni Piccioni (1549-1619)	Udite, lagrimosi Spirti d'Averno		5	italian	Hypodorian	Score + Parts