Feeding wild birds

[penjikent]

Hello everyone,

Does anyone have any advice on how to attract birds to a bird feeder? I have one just outside my kitchen window. It is pretty unobstructed, but, for some reason the local birds just don't see it. (It's too bad too because Portland - the city where I live - is quite brutal to birds and this winter is an absolute killer and the birds sure could use an additional feeding place.)
Are there any particular colors birds are attracted to? Perhaps, my feeder is the wrong shape? (It's just a tray).

Will appreciate any ideas.