Schedule block Timeline colour rendering is broken on Internet Explorer.

Steps:
1. Go to Studio demo page in Studio UI.
2. Switch to Edit mode.
3. Select a Schedule block.
4. Examine the Timeline that appeared.
5. Move the slider (optional).
Actual: Everything on the left side of the slider is blue and white on the right side.
Expected: Timeline is gray with green 'past' elements and purple 'future' elements.

Remarks: Please see attached screen-shot.