The most common and most likely answer to this crossword clue is the 6 letter word CERISE
I've seen this crossword clue in The Times
C
E
R
I
S
E
More clues leading to the result CERISE
- Part of ulcer is extremely red
- Visiting church raised father’s tone
- Something like cardinal, perhaps, to advance on church
- Light red coating everyone initially applied to 4
- Father about to enter church for shade
- This French rebel is a red
- Tone of church is encapsulated by religious teaching
- Colour of cherry is seen occasionally
- With passion rising during examination of the past, see red
- Colour of cherry in seed oddly
Buddy explains!

The straight part
We know that "tone" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case tone = cerise.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 CERISE mean?
CERISE noun- A deep, bright red colour tinted with pink.
- Cherry-colored; a light bright red; -- applied to textile fabrics, especially silk.