spriteelement.sprite ... can only be used on sprite-button?

[ownlyme]

i have a table with 4000 entries for a graph and want to replace single sprites with different colors,
but i cant change the sprite of a "sprite" element, it says it only works with sprite-buttons.
i cant regenerate the whole table because it lags half a second.
maybe a way to remove the padding from sprite-buttons?

edit: okay, i did it with progressbars, the creation of the frame is also much faster, but the game's fps drop if there are more than 4 graphs open
i guess this will do it.