Strange purplish brown colour. You’re making that up, it’s odd (8)
I believe the answer is:
peculiar
This might be a double definition.
'strange purplish brown colour you're making that up' is the first definition.
'peculiar' can be an answer for 'strange' (I've seen this before). I am unsure of the remainder of the definition.
'it's odd' is the second definition.
(I've seen this before)
Can you help me to learn more?
(Other definitions for peculiar that I've seen before include "Strange, different from the norm" , "Characteristic" , "sick" , "Strange, I clear up" , "I clear up, being odd" .)