2D colourmap of TA experimental data of all- trans (AT) or LA-BR. In the 2D color maps, the X-axis represents probe wavelength (or wavenumber) while the Y-axis represents the delay between pump and probe. Initial 500 fs pump-probe delay is linear, and the rest of the axis is logarithmic. The absorption difference is color-coded: the color bar at the right of the map presents the value of absorption difference.