Yellow like branches on a prince blue holly tree and very thin growth
Certified GKH Gardening Expert
This appears to be a severe set of nutrient deficiencies. Does this get much sun? They will tolerate shade, but they need some direct sunlight as well.
This article will help you to care for these: https://www.gardeningknowhow.com/ornamental/shrubs/holly/growing-meserve-blue-hollies.htm