The most common and most likely answer to this crossword clue is the 5 letter word MOUSE
I've seen this crossword clue in The Guardian
M
O
U
S
E
More clues leading to the result MOUSE
- Timid person I click with?
- Think about love as a timid person
- Timid chap getting married by river
- Computer accessory needed by famous engineer
- Rodent marks domestic ’abitat?
- Medical officer to exploit timid creature
- Way to work and deploy some revolutionary vermin control
- Married Yorkshire banker – something clicked!
- Very little time to exploit computer accessory
- Second application for computer device
Buddy explains!

The straight part
We know that "light brown in colour" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case light brown in colour = mouse.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does MOUSE mean?
MOUSE noun- Any small rodent of the genus Mus.
- A member of the many small rodent and marsupial species resembling such a rodent.
- A quiet or shy person.
- (plural mice or, rarely, mouses) An input device that is moved over a pad or other flat surface to produce a corresponding movement of a pointer on a graphical display.
- Hematoma.
- A turn or lashing of spun yarn or small stuff, or a metallic clasp or fastening, uniting the point and shank of a hook to prevent its unhooking or straightening out.
- A familiar term of endearment.
- A match used in firing guns or blasting.
- A small model of (a fragment of) Zermelo-Fraenkel set theory with desirable properties (depending on the context).
- A small cushion for a woman's hair.
- To move cautiously or furtively, in the manner of a mouse (the rodent) (frequently used in the phrasal verb to mouse around).
- To hunt or catch mice (the rodents), usually of cats.
- To close the mouth of a hook by a careful binding of marline or wire.
- To navigate by means of a computer mouse.
- To tear, as a cat devours a mouse.