washed out colours when uploading?

i edit my photos with cs5,lightroom and snapseed but im having the trouble when i upload to weebly the colours are really washed out,they look fine when i preview them in windows picture viewer but as soon as i upload them they are really dull.when i edit them with lightroom and export the pictures to a folder,it saves a tiff file which seems to be a washed out version along with a jpeg of the exact edit,so i make sure i upload the jpeg and its just like i uploaded the other tiff version.i resize them using irfanview which has worked well in the past so i dont know why its started doing it.i just had a closer look,maybe its something to do with weebly?

does anyone know whats going on?