You'll need to experiment more with combinations because mid-tone skin contains more color variations. Have the following colors handy:  Red Yellow Blue White Burnt Umber Raw Sienna Use a mixing palette or whatever surface you have available. A good alternative to a mixing palette is a sturdy piece of cardboard. Create a blob of each color onto your palette. Create an orange color by mixing equal portions of red and yellow. Clean your brush after gathering each color in a cup of water. Slowly mix in blue paint, in small increments. Depending on how dark you are aiming for, consider using a very small amount of black paint. Have the prospective skin tone that you are trying to emulate nearby. Compare the base you've created with the tone you are shooting for. If you're using a photograph, be aware of the lighting from the photo. Add small amounts of red if needed at all. It's always easier to add in small amounts than to start from scratch. Mix equal parts of burnt umber to raw sienna.  This combination will create a darker concentrate. Slowly add this mixture to your base as you see fit. Use this combinations as an alternative to blue. For a greater olive effect add the smallest amount of yellow mixed with green. Keep creating different colors until you have about five different skin tones that you like. It might be easier for you to have a few colors to choose from then limiting yourself to one. Use the color or colors you've created as a skin tone for your painting.
جهز مجموعة من ألوان الرسم. اجمع ألوانك. اخلط اللون الأحمر مع اللون الأصفر. أضِف اللون الأزرق. قارن الألوان. أضِف اللون الأحمر حسب الحاجة. اصنع درجة لون زيتوني داكن. قُم بعمل بعض التجارب حتى تصل إلى نتيجة مُرضية بالنسبة لك. ارسم لوحتك.