Variation of RV as a function of order number for CARMENES visible channel. The slope of the RV-log(λ) correlation is the CRX value. Eight CARMENES spectra are shown and colour-coded based on stellar rotational phase. The upper and lower borders of the shaded grey region are the slopes of the spectra with the highest and lowest RV variations, as indicated by the green and blue points respectively. An important point to note is that the two outer extremes of the shaded grey area will not converge at redder wavelengths. The same eight spectra are used to reconstruct the first low-resolution spot map in Fig. 6.