my buyer has 2 negative feeback comments, but they show as positive, WHY?

[fluff-e-duck]

I state contact must be made within 24hr of winning bid. I messaged buyer, asking for postcode and giving postage options should they wish them. No response. I read he has 2 negative feedback comments but they appear as green stars, WHY? if they are negative would people leave positive? I am worried now he wont buy or pay etc. I have just started back on ebay after a few years and am not so sure I remember what to do or in this case. it all seems more complicated and expensive now 😞