Tested in Google Chrome 19.0.1084.52 m on Windows 7 x64
Steps to reproduce:
This behaviour is confusing (if it's correct behaviour), because people won't assume that clicking in one textbox will modify the values in other text boxes.
It is confusing. Something need to change about it, but I'm not sure how. Let me explain why we landed on the current behavior.
At first, we had simple start and end boxes, but as we tested we found that, the typical use of a linear gradient is to have one color and use a lighter/darker shade for the different start/end values.
So we tried to dumb down the idea of linear gradients in ThemeRoller's UI. We switched to a single color selector with a slider that allows the user to change how drastic the light-to-dark/dark-to-light transitions are. What the slider actually does is this: we take the color the user gave us and we increase the brightness of the start color and decrease the brightness of the end color. If the slider is to the left of the midway point, this behavior is reversed.
Then we were left with the edge case of users wanting to dial in start/end values perfectly. So we compromised. We put our single-color-with-slider front and center and left the start/end dropdown as a back up.
The workflow in my head looks like this:
The start and end colors do change while changing the base color so that when the user goes to fine-tune the resulting gradient, they can tweak the actual start/end color.
The reason the start/end boxes match the base color box exactly on the user's first go is because the slider is defaulted to the middle position (flat gradient).
That was a long and winded, (and probably uneccessarily detailed) explanation of why it behaves this way.
I want to be clear, I'm not saying it's not confusing. I'm just writing down all the details so we might discuss how else to solve the problem. Thoughts anyone? @toddparker?