client.on('messageReactionAdd', (messageReaction, user) => {
    const { message } = messageReaction

    if (!message.author.bot || user.bot) return;

    // From a JSON file, parsed above:
    //colorRoles: { "🔵": "BLUE", "🟢": "GREEN", "🔴": "RED", "🟡": "YELLOW" }
    const guildRoles = message.guild.roles.cache
    const emojiName = messageReaction.emoji.name

    // If the emoji is 🔵, 🟢, 🔴, or 🟡
    if (colorRoles.hasOwnProperty(emojiName)) {
        // The GuildMember that added the Reaction
        const guildMember = messageReaction.message.guild.members.cache.find(member => member.id === user.id)

        // Find that color's Role name, then add it to the GuildMember
        const addRole = guildRoles.find(role => role.name === colorRoles[emojiName])
        guildMember.roles.add(addRole)

        // Filter colorRoles that aren't the selected one, then remove them from the GuildMember
        const removeRoles = guildRoles.filter(role => Object.values(colorRoles).filter(color => color !== colorRoles[emojiName]).includes(role.name))
        guildMember.roles.remove(removeRoles)
    }

    // Remove other color role reactions by this user (ex. blue is already selected; remove blue when clicking green)
    // Omitted (working)
})