LIES: I really really like how the color combination works.

HONESTY: "I may be a little strict" Hmm, well, the graphic is despeckled.
I recommend saving it as ".PNG" it uses low byte size but High quality. OR just use JPEG (JPG) but save it as "MAX Quality"....although, it may take quite a little more size.

==== There are ways manipulate the byte size but you need proper graphic tools. ====

..>Secondly: I am NOT anti-pink but Pink for halloween doesnt match (Even though it doesnt really matter if its halloween or not).

The neon skyblue and black is a good combo but the pink just takes it away. (Distractive graphic)

(I think that all I have to say about the colours)

..>Thirdly: The banner is like one of them graphics that "kind-of" hurts the eye because as I said before, the colours doesn't match.
For example: If you are to use a warm type colour such as RED then make the other one as ORANGE. (Smooth preffered) Green is fine, too. But ehh....
(((((If you took Graphic Arts before then you should know what I meant, refer back to Primary and Secondary Colours.)))))


My last comment: You're in position of this guild, the choices are for you to make. So, don't take all the things I said seriously, who knows, I might be wrong, too.