Hello,
1. The size of the logo depends on three factors:
1) The maximum specified width in the “Logo width” option (https://prnt.sc/23pdtty). The logo cannot be wider than the “Logo width” value.
2) The height of the row in which this logo is located (https://prnt.sc/23pdvit). The logo cannot be higher than the row of the header in which it is located.
3) The dimensions of the logo image and its aspect ratio (https://prnt.sc/23pemgh). The logo cannot become larger than its physical dimensions.
The “Logo width” option only sets the maximum width of the logo. For example, if its physical image size is 280px (https://prnt.sc/23pf0iz), then with this option you can set the size from 10px to 280px. In this case, any other value higher than 280 px will not do because for this you need to increase the physical size of the image in the image editor.
2. Navigate to Theme Settings -> Typography -> Advanced -> create a rule with the “Main navigation links” and set the color you want – https://take.ms/4T2PQ
Kind Regards