Changes in the educational landscape due to the COVID-19 pandemic open opportunities to create instructional materials that will make teaching and learning easier. The use of a learning tool such as Learning Management System (LMS) as the online classrooms of students is one of the essentials in an online learning environment. Utilizing an action research design, this study aims to assess the designed Cloud-based Centralized Collaborative Classroom and Communication - Learning Management System (C5-LMS) using Google Classroom. The assessment of C5-LMS was anchored on the extended Unified Theory of Acceptance and Use of Technology (UTAUT) model. The respondents of the study were the faculty members, supervisors, and students of a certain college that utilized the pilot of C5-LMS design. Findings of the study revealed that the C5-LMS via Google Classroom gained "acceptability" among the respondents in terms of extended UTAUT constructs. Users' overall acceptance of the C5-LMS when grouped according to their roles revealed that the teacher-respondents' rating is highly acceptable, nevertheless, the superior and students' assessment is acceptable. Moreover, all the respondents confirmed that the C5-LMS has the following capabilities that corroborate the initial findings: collaboration, communication, facilitation tasks, usefulness, easy navigation, and monitoring system.