【界面UI】聊天频道颜色语义：分频道的色彩规范与暗色适配

local CHAT_COLOR = {
    world  = { 230, 200, 60 },
    guild  = { 120, 220, 130 },
    private = { 200, 130, 230 },
    system = { 230, 90, 90 },
}
local function appendChat(channel, text)
    local c = CHAT_COLOR[channel] or CHAT_COLOR.world
    GUI:Text_Create(chatLayer, "c" .. seq, 8, 0, text, 14, c)
end

local DARK_COLOR = {
    world  = { 240, 220, 100 },
    guild  = { 150, 235, 160 },
    private = { 220, 160, 240 },
    system = { 245, 120, 120 },
}
local function applyTheme(dark)
    CHAT_COLOR = dark and DARK_COLOR or CHAT_COLOR
end