This image shows two adult females with a juvenile. I say this with some caution. The top bird has an orange beak with orange feet. The bottom two birds have black beaks with orange feet. Wells (1999) says adult feet are grey-green. Collar & Boesman (2020) say adult feet are buff-orange. Juniper and Mike Parr (1998) say legs are yellowish-brown. I have seen adults with both type of feet colours, hence my comment above about two female adults.
I suspect more work is required on foot colouration in adults with respect to breeding issues, geographical location and maturity. Juveniles and immature birds have orange feet. Collar & Boesman (2020) say that maturation takes 2-4 years and this may account for foot colour confusion in literature.
1. K. Eduard Linsenmair, Martin Heil, Werner M. Kaiser, Brigitte Fiala, Thomas Koch, Wilhelm Boland (2001). Adaptations to biotic and abiotic stress: Macaranga‐ant plants optimize investment in biotic defence. Journal of Experimental Botany, Volume 52, Issue 363, Pages 2057–2065.
2. Brigitte Fiala, Ulrich Maschwitz, Tha Yaw Pang. The association between Macaranga trees and ants in South-east Asia. Available here: http://naturedocumentaries.org/wp-content/uploads/2014/09/Fiala_association_Macaranga.pdf
3. Wells, D.R. (1999) The birds of the Thai-Malay Peninsula: Vol. 1 (Non-Passerines). Christopher Helm, London
4. Collar, N. and P. F. D. Boesman (2020). Blue-crowned Hanging-Parrot (Loriculus galgulus), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology
5. Tony Juniper and Mike Parr. (1998) Parrots: A Guide to Parrots of the World. Yale University Press.