Study of Guselkumab in Skin of Color Participants With Moderate-to-severe Plaque and/or Scalp Psoriasis

Inclusion Criteria:

Have a diagnosis of plaque psoriasis (with or without psoriatic arthritis [PsA]) for at least 6 months before the first administration of study drug
Self-identify as non-white or non-caucasian
Be a candidate for phototherapy or systemic treatment for psoriasis
Have an involved body surface area (BSA) greater than or equal to (>=) 10 percent (%), psoriasis area and severity index (PASI) >=12, investigator global assessment (IGA) >=3 at screening and at baseline (Cohort A), or have a scalp surface area >=30%, psoriasis scalp severity index (PSSI) >=12, scalp specific investigator global assessment (ss-IGA) >=3, and one plaque outside of the scalp at screening and at baseline (Cohort B)
Agree not to receive a live virus or live bacterial vaccination during the study, or within 12 weeks after the last administration of study intervention
Agree not to receive a Bacillus Calmette-Guérin (BCG) vaccination during the study, and within 12 weeks after the last administration of study intervention

Exclusion Criteria:

Has a nonplaque form of psoriasis (example: erythrodermic, guttate, or pustular)
Has received ustekinumab, ixekizumab, secukinumab, or brodalumab within 12 weeks of first dose of study drug
Has a history or current signs or symptoms of severe, progressive, or uncontrolled renal, cardiac, vascular, pulmonary, gastrointestinal, endocrine, neurologic, hematologic, rheumatologic, psychiatric, or metabolic disturbances
Participant has known allergies, hypersensitivity, or intolerance to guselkumab or its excipients
Has or has had a serious infection (example: sepsis, pneumonia or pyelonephritis), or has been hospitalized or received intravenous antibiotics for an infection during the 2 months before screening