## 3 Results and Discussion
The calculated values of hue angle, color saturation and saturation are given in Table 5.  
The hue angle values of both groups of samples were approximately the same before drying. Maple wood exhibited lower values. During drying, there was a remarkable decrease in the value of the hue angle towards the red-brown color of maple wood during high-temperature drying. Similar results were observed in [12], where a remarkable color change in birch samples was confirmed. During the drying of mature wood (_MW_), there was a noticeable decrease in the hue angle towards the red-brown color. It changed from 72\({}^{\circ}\) before drying to 57.4\({}^{\circ}\) after drying on _MW_. As also shown in [12], the combination mode (hot-air drying and high-temperature drying) could remarkably reduce the color change in the early phase of drying process. There were minimal differences in hot-air drying. There were minimal differences in hot-air drying. The values of \(S_{ab}\) and \(C^{*}_{ab}\) decreased in both wood species during hot-air drying 60 \({}^{\circ}\)C (Table 5). During high-temperature drying (120 \({}^{\circ}\)C) the values increased. A more significant increase was seen in the maple wood. Color changes of hornbeam and maple during hot-air drying (60 \({}^{\circ}\)C) and high-temperature drying 120 \({}^{\circ}\)C are shown in Figure 5. A similar result was evident in [19], where a red coloration of maple wood was discovered when it was exposed to high temperatures. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multicolumn{2}{c}{**Samples**} & \multicolumn{2}{c}{**Color**} & \multicolumn{3}{c}{**Before Drying**} & \multicolumn{3}{c}{**After Drying**} & \multirow{2}{*}{**Count**} \\ \cline{3-3} \cline{5-10} \multicolumn{2}{c}{} & \multicolumn{1}{c}{**Coordinates**} & & & \multicolumn{1}{c}{**Mean**} & & \multicolumn{1}{c}{**Standard**} & \multicolumn{1}{c}{**Sample**} & \multicolumn{1}{c}{**Mean**} & \multicolumn{1}{c}{**Standard**} & \multicolumn{1}{c}{**Sample**} \\ \cline{3-10} \multicolumn{2}{c}{} & \multirow{2}{*}{Hornbeam} & \(L^{*}\) & **69.8** & 1.503 & 2.259 & **67.0** & 3.277 & 10.737 & 30 \\  & & \(a^{*}\) & **8.3** & 0.747 & 0.558 & **6.6** & 0.610 & 0.372 & 30 \\  & & \(b^{*}\) & **27.7** & 0.361 & 0.130 & **21.1** & 0.946 & 0.896 & 30 \\ \cline{2-10}  & & \(L^{*}\) & **66.1** & 1.842 & 3.393 & **62.2** & 0.587 & 0.344 & 30 \\  & & \(a^{*}\) & **12.7** & 0.669 & 0.448 & **12.4** & 0.541 & 0.293 & 30 \\  & & \(b^{*}\) & **33.0** & 1.129 & 1.275 & **27.3** & 0.158 & 0.025 & 30 \\ \hline \multirow{4}{*}{**120 \({}^{\circ}\)C**} & \multirow{2}{*}{Hornbeam} & \(L^{*}\) & **69.3** & 0.533 & 0.284 & **60.6** & 1.373 & 1.886 & 30 \\  & & \(a^{*}\) & **8.7** & 0.507 & 0.257 & **8.8** & 0.567 & 0.322 & 30 \\  & & \(b^{*}\) & **26.3** & 0.706 & 0.498 & **25.4** & 0.083 & 0.007 & 30 \\ \cline{2-10}  & & \(L^{*}\) & **75.3** & 0.816 & 0.666 & **56.8** & 1.202 & 1.444 & 30 \\  & & \(a^{*}\) & **8.7** & 0.422 & 0.178 & **12.2** & 0.446 & 0.199 & 30 \\  & & \(b^{*}\) & **27.9** & 0.501 & 0.251 & **25.5** & 0.620 & 0.385 & 30 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Average values and basic statistical characteristics of the coordinates of the color space \(L^{*}\), \(a^{*}\) and \(b^{*}\) for samples from hornbeam and maple.