Very bright Roman figures (5)
I believe the answer is:
vivid
'very bright' is the definition.
(I've seen this before)
'roman figures' is the wordplay.
I cannot really see how this works, but
'roman figures' could be 'vi' (Roman numerals for 6) and 'vi' is found within the answer.
The remaining letters 'vid' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for vivid that I've seen before include "Strong and bright, colour perhaps" , "Brilliantly coloured - full of life" , "Presenting a clear and striking picture" , "Intense" , "Intensely deep/bright" .)