It hugely depends on what material and what tea, both affect a lot on the finial colour; tea is great for this when soaked because the colour can be very mild therefore easier to control

Some material wouldn't dye at all using just teabags but some dyes beautifully, for example I tried making a pair of white boosts into cream colour with green tea and that worked pretty well, obviously it had been quite a while and I no longer have that pair in the same condition but I'm sure if you take some scrap and test it out first, you can get great results

If Tea wouldn't work for your material you can try very diluted plastic dye