Rings of Minor Proficiency

Rings of Proficiency are small rings that can be fit around one's finger. They are made of alloyed gold and have glowing ruin-like markings on them that can be in one of six colors.
A creature wearing a ring of minor proficiency can add a +1 to any skill check or saving throw involving the ability matching the color of the ring. The creature can do so once per day. Invoking the ring may be done after rolling, but before knowing the outcome of the check.
Each ring matches one abilities:

• Red: Strength
• Green: Dexterity
• Orange: Constitution
• Purple: Intelligence
• Blue: Wisdom
• Yellow: Charisma