Very bright; intense (5)
I believe the answer is:
vivid
I believe this is a double definition.
'very bright' is the first definition.
(I've seen this before)
'intense' is the second definition.
(I know that intense can be written as vivid)
(Other definitions for vivid that I've seen before include "Brilliant" , "Very bright and colourful" , "Brightly coloured" , "Intensely deep/bright" , "Fresh and bright" .)