Z-index on color palette

[mhkeller]

Granted the use of this many colors is obscene but the z-indexing is off if you exceed more than few rows.

[yanofsky]

this is more important than just aesthetics.

The swatches under the "color" and "right axis" can't be selected

[mhkeller]

The z-index battle on this one is pernicious due to nested elements. As a quick fix, I've added the following style adjustments on here.

The width is specific to using the six color scales but the other adjustments (putting it above the colorpicker) could be part of a more generic solution. One big issue, though, is if you have a color picker as the first element, such as on the chartbuilder-ui demo page, and your els will go off the top of the page.

.cb-colorpicker-els
    width 260px
    top -310px
    &.active::after
        top auto
        bottom 7px