Funding for this research was provided by:
City University of Hong Kong (9360157)
Article History
Received: 28 September 2022
Revised: 2 January 2023
Accepted: 5 January 2023
First Online: 1 February 2023
Conflict of interest
: H.-L.L. and W.K. are the inventors of a US Patent (Patent No.: US 11,475,598) that has been filed regarding the color coding system described in this article. The remaining authors declare no competing interests.