Response: The Rainbow Bathblossom in Metaphor: ReFantazio cannot be bought or ground. It is a legendary bath salt that can be obtained as a reward for completing a ranked battle in the Coliseum.

Here are the detailed steps to obtain and use bath salts in Metaphor: ReFantazio:

### Step-by-Step Guide to Using Bath Salts

1. **Wait for Nighttime**:
– Ensure it is nighttime when your party is resting at a campsite. This is the only time you can use the bath.

2. **Locate the Bath**:
– The bath is located at the back of the deck on the Gauntlet Runner.

3. **Add Bath Salts**:
– Once you have located the bath, add the desired bath salts to the water. Each bath salt has a specific effect and location.

4. **Choose the Right Bath Salt**:
– Different bath salts offer various stat boosts:
– **Silento, near Virga Island**: +2 Strength or +2 Magic.
– **Komero, near Martira**: +2 Agility.
– **Lingo, near Grand Trad**: +2 Luck.
– **Inudo, near Brilehaven**: +2 Endurance.
– **Malva, near Altabury**: +4 Max HP.
– **Rainbow Bathblossom (Coliseum)**: +2 Max HP, Max SP, and St/Ma/En/Ag/Lk.
– **Uncle Electreux’s Wondersalts (Silento)**: +2 Strength.
– **Niflheim Plunge (Silento)**: +2 Magic.
– **Hell’s Boiling Bath Bomb (Inudo)**: +2 Endurance.
– **Hot Spring Report: Lifelong Pals (Malva)**: +4 Max HP.

5. **Check Vendors Regularly**:
– Bath salts are limited and can only be purchased from specific vendors in villages you pass through. Check these shops regularly to stock up on the bath salts you need.

6. **Use Bath Salts Strategically**:
– Use the bath salts strategically to maximize your character’s stats. Bath salts can provide permanent stat boosts, which can significantly impact your gameplay, especially in late-game boss fights.

By following these steps, you can effectively use bath salts to enhance your character’s stats in Metaphor: ReFantazio.