I'm wondering if there is a way to select a color off of the gradient slider without adding another slider tab. I just want to make the middle slider tab the same color as whats right next to it without moving it. I don't know if this is even possible or if my question makes any sense.
You can't easily do this 'without creating another slider tab', but... if you create a new, temporary slider tab at the point where you wish to sample the colour, then drag the colour from the 'colour' palette (which will now be the colour of the new tab that you just created) to the tab that you wish to recolour and then delete the tab that you just created then that will give you the effect that you are looking for. Hope that's clear, quite tricky to explain in words.