I just added the extra colours into the linear gradient syntax. Linear gradients are indeed a little complex but with trial and error you can soon tweak things into position when you have an example to work from
to right = from left to right horizontally
#0ff 83px = first 83px is #0ff
'#0059dd` 83px = now abruptly change to #0059dd
#0059dd 86px = continue same color for 3 pixels
#fff 86px = abruptly change to #fff
#fff 174px = continue same color up to 174px with #fff
#0059dd 174px = abruptly change to #0059dd
#0059dd 177px = continue for 3 pixels
#f0f 177px = abruptly change to #f0f for the rest from 177px onwards.